15th European Workshop on Chemistry EWPC 15/2018

March 14-16, 2018 Uppsala University, Uppsala, SWEDEN

European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Dear Participants of the EWPC-15, The long tradition of workshops previously held in Kaiserslautern (2004), Bonn (2005), Leipzig (2006), Zandvoort (2007), Regensburg (2008), Florence (2009), Budapest (2010), Münster (2011), Rennes (2012), Regensburg (2013), Sofia (2014), Kassel (2015), Berlin (2016), and Cluj-Napoca (2017) will be continued with the 15th European Workshop in Phosphorus Chemistry in Uppsala, Sweden. This traditional workshop series has contributed to the strong position of the European research community and allowed for a fruitful exchange of ideas, opinions and excellent discussions. The topics of this conference cover organic, inorganic, polymer, and material chemistry as well as biological research.

The program comprises 30 oral presentations from experienced researchers and PhD students, and a round table discussion on the future of phosphorous chemistry. The first evening will be concluded by a “Rektorsmottagning”, a Principals reception, at the University Main Building, which was inaugurated in 1887. The second day full of scientific program ends with a convivial conference dinner at the Restaurant Sven Dufva, located at the Science Park Uppsala. The last day of science will end with the traditional awards for the Best Posters, Best Chair and Best Presentations. Our aim is to create a vivid atmosphere that fuels discussions in this multidisciplinary field of research. We are aiming to re-inforce the (European) network of researchers by this annual conference. A specific goal of this conference series is, to provide young researchers a platform to present and discuss their science with peers and experienced researchers, alike. We would also like to thank the Swedish Research Council (Vetenskapsrådet) and our sponsors for their generous support. Sincerely, The organizing committee

Organizing committee Prof. Sascha Ott (Uppsala University) Doc. Andreas Orthaber (Uppsala University) Prof. J. Chris Slootweg (University of Amsterdam)

Dr. Arvind Kumar Gupta, Dr. Joshua Green, Dr. Anna Arkhypchuk, Muhammed Anwar Shameem, Daniel Morales-Salazar, Nicolas D Imperio, Juri Mai, Martin Obermeier, Sebastian Wagner, and Alessandro Nardin

Uppsala University, SWEDEN March, 14th March, 15th March, 16th 12:30-14:00 Registration 09:00 O9 Heeran (Durham) 09:00 O22 Blum (Stuttgart) 14:00 Opening 09:20 O10 Holtrop (Ansterdam) 09:20 O23 O´Fearraigh (Dublin) 09:00 - 10:20 09:00 - 10:20 14:10 O1 Baker (Zurich) 09:40 O11 Chadwick (Bristol) 09:40 O24 Mai (Uppsala) 14:00 - 15:30 14:30 O2 Szych (Rostock) 10:00 O12 Keweloh (Münster) 10:00 O25 Buszaki (Budapest)

14:50 O3 Schoemaker (Dresden) 10:20-11:00 Break 10:20-11:20 Poster Session + Coffee Break C o

15:10 O4 Ordyszewska (Gdansk) 11:00 O13 Faria (Oxford) 11:20 O26 Vetter (Dublin) European Workshop on Phosphorus Chemistry - EWPC 15/2018 15:30-16:00 Coffee Break 11:00 - 12:00 11:20 O14 Begum (Bonn) 11:20 - 12:20 11:40 O27 Arguello Velasco (Wroclaw) n f 16:00 O5 Cozar (Bilbao) 11:40 O15 Buss (Münster) 12:00 O28 Schwarz (Graz) e r 16:20 O6 Rádai (Budapest) 12:00-13:30 Lunch 12:20 Break e n

16:00 - 18:10 16:40 O7 Papke (Berlin) 12:40 Closing c 17:00 O8 Kargin (Kassel) 13:30 O16 Krämer (Regensburg) 13:00 END e S

17:20 Round table 13:30 - 14:30 13:50 O17 Vanni (Florence) c Uppsala University, SWEDEN 14:10 O18 Hierlmaier (Regensburg) h e

18:30 Rektorsmottagning 14:30-15:30 Poster session + Coffee Break d Universitetshuset 15:30 KL1 Kivala (Erlangen) u l March 14-16

15:30-16:30 e 16:00 KL2 Romero-Nieto (Heidelberg) E

16:30-17:00 Break W 17:00 O19 Mokrai (Rennes) Engelska Parken Ihresalen (Conference lectures) P

17:00-18:00 17:20 O20 Crumbach (Aachen) C

Thunbergsvägen 3H, 752 38 Uppsala -

17:40 O21 Coburger (Leipzig) 1 5 ,

19:30 Dinner Sven Dufva U p p

Universitetshuset/ University hall s a l

(Welcome reception) a Restaurant Sven Dufva (Conference Dinner) Biskopsgatan 3, 753 10 Uppsala Dag Hammarskjölds väg 40, 752 37 Uppsala European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16 List of Participants Last Name First Name University Contribution Email

Arguello Ruben Wroclaw University O27 [email protected] Bagi Peter University of Budapest P1 [email protected] Baker Matthew ETH Zürich O1 [email protected] Begum Imtiaz University of Bonn O14 [email protected] Blum Markus University of Stuttgart O22 [email protected] Brand Alexander Münster University P2 [email protected] Brodie Claire Durham University P3 [email protected] Buss Florenz Münster University O15 [email protected] Buzsaki Daniel University of Budapest O25 [email protected] Chadwick Ailis University of Bristol O11 [email protected] Chojetzki Lukas Rostock University P4 [email protected] Cicac Hudi Mario University of Stuttgart P5 [email protected] Coburger Peter Leipzig University O21 [email protected] Cozar Abel de Universidad del Paiso Vasco O5 [email protected] Crumbach Merian Aachen University O20 [email protected] D Imperio Nicolas Uppsala University P6 [email protected] Eilrich Volker Leipzig University P7 [email protected] Faria Erica University of Oxford O13 [email protected] Fassbender Jan University of Bonn P8 [email protected] Feil Christoph University of Stuttgart P9 [email protected] Guo Chunxiang TU Dresden P10 [email protected] Habraken Evi University of Amsterdam P11 [email protected] Heeran Michael Durham University O9 [email protected] Heift Dominikus Durham University P12 [email protected] Henyecz Reka University of Budapest P13 [email protected] Herbay Reka University of Budapest P14 [email protected] Hierlmeier Gabriele University of Regensburg O18 [email protected] Hinz Alexander University of Oxford P15 [email protected] Holtrop Flip University of Amsterdam O10 [email protected] Ho Luong Ohong Braunschweig University P16 [email protected] Isenberg Stefan University of Kassel P17 [email protected] Junker Philip University of Bonn P18 [email protected] Kaaz Manuel University of Stuttgart P19 [email protected] Kaniewska Kinga Gdansk Univ. of Technology P21 [email protected] Kargin Denis University of Kassel O8 [email protected] Keweloh Lukas Münster University O12 [email protected] Kivala Milan University of Nurnberg KL1 [email protected] Krämer Barbara University of Regensburg O16 [email protected] Kunzmann Robert University of Bonn P22 [email protected] Leitl Julia University of Regensburg P23 [email protected] Lowe Pawel Münster University P24 [email protected] Mai Juri Uppsala University O24 [email protected] Maslanka Marta Wroclaw University P25 [email protected] Mehlmann Paul Münster University P26 [email protected] Mei Yanbo ETH Zürich P27 [email protected] Meissel Hubert University of Bristol P28 [email protected] Miles-Hobbs Alexandra University of Bristol P29 [email protected] Mokrai Reka University of Rennes O19 [email protected]

Uppsala University, SWEDEN European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Muller Henrik Rostock University P30 [email protected] O`Fearraigh Martin University College Dublin O23 [email protected] Ordyszewska Anna Gdansk Univ. of Technology O4 [email protected] Papkel Martin Freie Universitet Berlin O7 [email protected] Piesch Martin University of Regensburg P31 [email protected] Popp John Leipzig University P32 [email protected] Radai Zita University of Budapest O6 [email protected] Romero-Nieto Carlos Heidelberg University KL2 [email protected] Rotering Philipp Münster University P33 [email protected] Scharnholz Moritz Rostock University P34 [email protected] Schmer Alexander University of Bonn P35 [email protected] Schoemaker Robin TU Dresden O3 [email protected] Schulz Jan Leipzig University P36 [email protected] Schwarz Elisabeth University of Graz O28 [email protected] Shameem Muhammad Uppsala University P37 [email protected] Stosiek Natalia Wroclaw University P38 [email protected] Szych Lilian Sophie Rostock University O2 [email protected] Szynkiewicz Natalia Gdansk Univ. of Technology P40 [email protected] Tambornino Frank University of Oxford P41 [email protected] Taube Clemens TU Dresden P42 [email protected] Tendyck Christian Münster University P43 [email protected] Toth Nora University of Budapest P44 [email protected] Tripolszky Anna University of Budapest P45 [email protected] Vanni Matteo CNR ICCOM O17 [email protected] Varga Bence University of Budapest P46 [email protected] Vetter Anna University College Dublin O26 [email protected] Vincent Kevin Durham University P47 [email protected] Wanat Weronika Wroclaw University P48 [email protected] Weinzierl Rudolf University of Regensburg P49 [email protected] Williams Sarah University of Bristol [email protected] Wilm Lukas Münster University P50 [email protected] Wilson Daniel University of Oxford P51 [email protected] Wise Dan University of Bristol P52 [email protected] Witteler Tim Münster University P53 [email protected] Wossidlo Friedrich Freie Universitet Berlin P54 [email protected] Ziegler Christoph University of Regensburg P55 [email protected] Ziolkowska Aleksandra Gdansk Univ. of Technology P56 [email protected] Adhikari Anup Kumar Regensburg University [email protected] Arkhypchuk Anna Uppsala University [email protected] Benko Zoltan Universitu of Budapest [email protected] Börger Jennifer Münster University [email protected] Bresien Jonas University of Rostock [email protected] Caporali Maria CNR ICCOM [email protected] Carmichael Duncan CNRS Ecole Polytechnique [email protected] Clausing Simon Uppsala University [email protected] Conti Riccardo ETH Zürich [email protected] Dielman Fabian Münster University [email protected] Eder Tobias Münster University [email protected] Green Joshua Uppsala University [email protected]

Uppsala University, SWEDEN European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Gudat Dietrich University of Stuttgart [email protected] Gupta Arvind Kumar Uppsala University [email protected] Hey-Hawkins Evamarie Leipzig University [email protected] Hissler Muriel Rennes University [email protected] Kafarski Pawel Wroclaw University [email protected] Kelemen Zsolt University of Budapest [email protected] Mehta Meera University of Oxford [email protected] Morales-Salazar Daniel Uppsala University [email protected] Muller Christian Freie Universitet Berlin [email protected] Nardin Alessandro University of Milan [email protected] Nyulaszi Laszlo University of Budapest [email protected] Obermeier Martin Uppsala University [email protected] Orthaber Andreas Uppsala University [email protected] Ott Sascha Uppsala University [email protected] Peruzzini Maurizio CNR ICCOM [email protected] Pringle Paul University of Bristol [email protected] Scheer Manfred Regensburg University [email protected] Serrano Ruiz Manuel CNR ICCOM [email protected] Schulz Axel Rostock University [email protected] Schulz Stephen TU Dresden [email protected] Slawin Alexandra MZ University of St Andrews [email protected] Slootweg Chris University of Amsterdam [email protected] Streubel Rainer University of Bonn [email protected] Szucs Rozsa University of Budapest [email protected] Wagner Sebastian Uppsala University [email protected] Weigand Jan J. TU Dresden [email protected] Wiliams Sarah Bristol University [email protected] Wolf Robert Regensburg University [email protected] Woollins Derek University of St Andrews [email protected] Wustrack Ronald Rostock University [email protected] Hauenstein Oliver CLARIANT Gold sponsor [email protected] Schmidt Christian CLARIANT Gold sponsor [email protected] Faradji Charly ITALMATCH CHEMICALS Gold sponsor [email protected] Monti Chiara ITALMATCH CHEMICALS Gold sponsor [email protected] Woodward Gary SOLVAY Gold sponsor [email protected] Harris Chris SOLVAY Gold Sponsor [email protected] Hansel Jan-Gerd LANXESS Silver sponsor [email protected]

Uppsala University, SWEDEN European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

ORAL PRESENTATIONS

Uppsala University, SWEDEN European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Bridged Triarylphosphines as Versatile Platforms for the Construction of Polycyclic Heteroaromatic Compounds

Milan Kivala,a,* Johannes Ascherl,a Tobias A. Schauba,b and Frank Hampela

aDepartment of Chemistry and Pharmacy, University of Erlangen-Nürnberg. Erlangen. Germany. bDepartment of Chemistry and Biochemistry, University of Oregon. Eugene. Oregon. USA. [email protected]

The incorporation of heteroatoms directly into the sp2- skeleton of polycyclic aromatic hydrocarbons (PAHs) provides a powerful tool – next to variation of their size and periphery and/or lateral decoration with various substituents – to manipulate their optoelectronic properties and supramolecular behavior.1,2 This is particularly relevant in the context of organic electronics for which -conjugated organic materials finely tuned in terms of their photophysical, redox, and self-assembly properties are of high demand. Rather surprisingly, the field of phosphorus-containing PAHs is still in its infancy, although such compounds often show strikingly different properties from their - containing counterparts such as the unique pyramidal geometry and the Lewis basicity of the phosphorus centre, providing for additional chemistry.3

We have recently identified various relatively simple bridged triarylphosphine derivatives as versatile building blocks for the construction of unprecedented phosphorus-containing PAHs.4 This contribution will address our respective synthetic efforts and the fundamental characteristics of the resulting compounds.

Acknowledgement This work was supported by the Deutsche Forschungsgemeinschaft (DFG) as part of SFB 953 “Synthetic Carbon Allotropes” and the “Solar Technologies Go Hybrid” (SolTech) initiative of the Free State of Bavaria. References 1 P. O. Dral, M. Kivala, T. Clark, J. Org. Chem. 2013, 78, 1894–1902. 2 M. Stępień, E. Gońka, M. Żyła, N. Sprutta, Chem. Rev. 2017, 117, 3479–3716. 3 T. Baumgartner, Acc. Chem. Res. 2014, 47, 1613–1622. 4 a) T. A. Schaub, E. M. Zolnhofer, D. P. Halter, T. E. Shubina, F. Hampel, K. Meyer, M. Kivala, Angew. Chem. Int. Ed. 2016, 55, 13597–13601; b) T. A. Schaub, R. Sure, F. Hampel, S. Grimme, M. Kivala, Chem. Eur. J. 2017, 23, 5687–5691; c) T. A. Schaub, S. M. Brülls, P. O. Dral, F. Hampel, H. Maid, M. Kivala, Chem. Eur. J. 2017, 23, 6988–6992.

Uppsala University, SWEDEN KL1 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Expanding the Net: Novel π-Extended Materials Based on Six- Membered Phosphorus Heterocycles

C. Romero-Nieto*

Organisch-Chemisches Institut, Heidelberg University. Heidelberg. Germany. [email protected]

-Extended organic architectures are a fascinating class of compounds that plays a fundamental role in the materials science. The efficient overlap of atomic orbitals along an extended net of polyaromatic systems enables outstanding properties such as strong luminescence and high charge mobilities. An efficient strategy to modulate the latter optoelectronic properties consists in embedding heteroatoms into the carbon scaffold. To that end, phosphorus atoms are particular interesting; e.g. they present an electron lone pair that is readily available for a variety of reversible post-functionalization reactions. As a matter of fact, we recently reported novel phosphorus- containing phenalenes whose optoelectronic properties (emission color, fluorescence quantum yield up to 0.8 and ambipolar redox properties) could be efficiently modulated by phosphorus post- functionalization.1

In this communication, I will report the synthesis of a new generation of π-extended architectures based on six-membered phosphorus heterocycles.2 Furthermore, I will present a detailed investigation of their structural and optoelectronic properties. All in all, I will describe the benefits of embedding six-membered phosphorus heterocycles into π-extended polyaromatic hydrocarbons. The new materials overcome the performances of our previously reported phosphaphenalenes; they exhibit, among others, remarkable electron-accepting properties and fluorescence quantum yields of up to 0.85.2

References 1 a) C. Romero-Nieto, A. López-Andarias, C. Egler-Lucas, F. Gebert, J.-P. Neus, O. Pilgram, Angew. Chem. Int. Ed. 2015, 54, 15872-15875; b) P. Hindenberg, A. López-Andarias, F. Rominger, A. De Cózar, C. Romero- Nieto, Chem. Eur. J. 2017, 23, 13919-13928; c) O. Larranaga, C. Romero-Nieto, A. De Cózar, Chem. Eur. J. 2017, DOI: 10.1002/chem.201703495. 2 a) P. Hindenberg, M. Busch, A. Paul, M. Bernhardt, P. Gemessy, F. Rominger ,C. Romero-Nieto, Submitted.

Uppsala University, SWEDEN KL2 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Lewis Adducts of the Parent Phosphine, PH3 A Crystallographic and Spectroscopic Study

Matthew Baker, Mark Bispinghoff, and Hansjörg Grützmacher *

Laboratory of Inorganic Chemistry, ETH Zürich. Vladimir-Prelog-Weg 1, 8093 Zürich. Switzerland. [email protected]

1 The first Lewis Adduct of phosphane, BCl3·PH3, was reported in 1890. Further reports have since discussed enthalpy of formation,2 vibration spectra,3 11B NMR spectra,4 and 1H NMR spectra.5 However, an overview of these adducts and their properties, including crystal structures and 31P NMR spectra, remains absent from the literature.

The crystal structures and NMR spectra of compounds of the type EX3·PH3 (E = B, Al, Ga, In and X = Cl, Br, I) will be discussed in detail.

31 Figure 2 Structure of BI3·PH3 Figure 2 P spectrum of BI3·PH3

Acknowledgement The authors gratefully acknowledge ETH for their financial support.

References 1 A. Besson, C. R. Acad. Sci., Paris, 1890, 110, 516-518 2 R. Höltje, Z. Anorg. Allg. Chem., 1933, 209, 241-248 3 a) P. A. Tierney, D. W. Lewis, D. Berg, J. Inorg. Nucl. Chem., 1962, 24, 1163-1169 b) J. E. Drake, J. L. Hencher, B. Rapp, J. Chem. Soc., Dalton Trans., 1974, 595-603 c) M. J. Taylor, S. Riethmiller, J. Raman Spect., 1974, 15, 370-376 4 J. D. Odom, S. Riethmiller, J. D. Witt, J. R. Durig, Inorg, Chem., 1973, 1123-1127 b) J. E. Drake, B. Rapp, J. Inorg. Nucl. Chem., 1974, 36, 2613-2615 5 J. E. Drake, J. Simpson, J. Chem. Soc. A., 1968, 974-979

Uppsala University, SWEDEN O1 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

[P(µ-NBbp)]2 - a PN biradicaloid synthesized from an acyclic precursor

Lilian Sophie Szych1, Ronald Wustrack1, Jonas Bresien1, Axel Schulz1,2, Alexander Villinger1 [email protected], [email protected] 1Institut für Chemie, Abteilung Anorganische Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany. 2Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, 18059 Rostock, Germany.

Group 15 open shell singlet biradicaloids of the type [P(µ-NR)]2 show an interesting and diverse reaction behaviour, for example towards bearing multiple bonds or when it comes to the activation of small molecules. They are usually synthesized by the reduction of chlorinated cycles of the type [ClP(µ-NR)]2. R is a sterically demanding substituent which ensures the kinetic stabilization of the reactive biradicaloid (Scheme 1).[1,2]

Scheme 1. Top: Reduction of the Bbp stabilized derivatives, leading to the biradicaloid. Bottom: Molecular structures of A, B, C; orange: phosphorus; blue: nitrogen; green: chlorine.

We are currently investigating the synthesis and reaction behaviour of a new biradicaloid, stabilized [3] with the Bbp substituent (2,6-bis[bis(trimethylsilyl)methyl]phenyl). Reducing the [ClP(µ-NR)]2 heterocycle using the “classical route”, we could indeed synthesize the desired biradical B. However, the reduction of the acyclic compound Bbp-N(PCl2)2 also leads to the biradicaliod, which represents a hitherto unknown route to this class of compounds. References [1] T. Beweries, R. Kuzora, U. Rosenthal, A. Schulz, A. Villinger, Angew. Chem. Int. Ed. 2011, 50, 8974–8978. [2] A. Hinz, R. Kuzora, A. Rölke, A. Schulz, A. Villinger, R. Wustrack, Eur. J. Inorg. Chem. 2016, 22, 3611–3619. [3] T. Agou, Y. Sugiyama, T. Sasamori, H. Sakai, Y. Furukawa, N. Takagi, J. Guo, S. Nagase, D. Hashizume, N. Tokitoh, J. Am. Chem. Soc. 2012, 134, 4120−4123.

Uppsala University, SWEDEN O2 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

New synthetic approaches to novel acyclic- and cyclo-polyphosphanes

Robin Schoemaker, Felix Hennersdorf, David Harting, Jan J. Weigand

Chair of Inorganic Molecular Chemistry, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Germany. [email protected]

The use of pyrazole-substituted phosphanes as P1-sources for the synthesis of neutral and cationic polyphosphorus frameworks represents an integral research field of our group.[1] The solvent dependent reaction of dipyrazolylphosphane 1 with dicyclohexylphosphane leads to the formation of polyphosphanes 2 and 3 (Scheme 1).

Scheme 1: Synthesis of triphosphane 2 and pentaphospholane 3 from dipyrazolylphosphane 1. Thus, reacting 1 with dicyclohexylphosphane in acetonitrile in a 1 : 2 ratio leads to triphosphane 2 via a protolysis reaction, while the 1 : 1 reaction in diethyl ether gives pentaphospholane 3 via a P-N/P-P bond metathesis reaction.[1a] Triphosphane 2 reacts with an excess of methyl triflate quantitatively to triphosphane-1,3-diium salt 4[OTf]2 (Scheme 2).

Scheme 2: Methylation of 2 and further reaction to give 5[OTf]2. Pentaphospholane 3 acts as a [Py-P] phosphinidene source to give in a subsequent reaction with [2] 4[OTf]2 the [PyP-PPy] inserted reaction product 5[OTf]2 (Scheme 2). The general and very versatile application of pyrazole-substituted phosphanes for the synthesis of novel polyphosphorus compounds is discussed. Acknowledgement We thank the European Research Council (ERC starting grand, SynPhos - 307616) for financial support. References 1 a) K.-O. Feldmann, J. J. Weigand, J. Am. Chem. Soc. 2012, 134, 15443−15456; b) K.-O. Feldmann, J. J. Weigand, Angew. Chem. Int. Ed. 2012, 51, 7545–7549; c) for a review on oligophosphorus chemistry see M. Donath, F. Hennersdorf, J. J. Weigand, Chem.Soc.Rev. 2016, 45, 1145–1172. 2 for similar diphosphinodiphosphonium dications see a) C. A. Dyker, N. Burford, M. D. Lumsden, A. Decken, J. Am. Chem. Soc. 2006, 128, 9632-9633; b) Y.-Y. Carpenter, C. A. Dyker, N. Burford, M. D. Lumsden, A. Decken, J. Am. Chem. Soc. 2008, 130, 15732-15741.

Uppsala University, SWEDEN O3 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Complexes with low-valent phosphorus ligands Reactions of chalcogenes with phosphanylphosphinidene transition metal complexes

Anna Ordyszewska,a Rafał Grubba,a Łukasz Ponikiewskia and Jerzy Pikiesa

a Department of Inorganic Chemistry, Faculty of Chemistry, Gdansk University of Technology, 11/12 Gabriela Narutowicza Street, 80-233 Gdansk, Poland e-mail: [email protected]

Reactions of transition metal complexes with chalcogenes (O, S, Se) were systematically investigated [1] notwithstanding the reactions of chalcogenes or chalcogene sources with complexes with low-valent phosphorus ligands are rare. For instance, Cummins reported on addition of S-atom into the triple bonded P-atom in [2] [P≡Mo{NAr(R)}3] yielding [S=P=Mo{NAr(R)}3] . Dimeric phosphinidene complex [{Pt(dppe)(μ- [3] PMes)}2] reacts with sulphur to give monomeric [Pt(dppe)(S3PMes)] . Sulphur also reacts with dinuclear manganese complex [Mn2(CO)8{μ-P(TMP)}] yielding dinucler complex bridged with (TMP)P=S ligand [4]. Ruiz et al. studied the reactivity of dinuclear molybdenum phosphinidene [5] complex with S8 . Herein, we made the first attempt to investigate the reactivity of phosphanylphosphinidene transition metal complexes towards chalcogenes and chalcogene sources. As an example anionic phosphanylphosphinidene tungsten complex reacts with elementary yielding new dimeric complex, where P-P bond cleavage occurs and phosphinidene P atom is surrounded by four selenium atoms.

Se

Acknowledgement The authors gratefully acknowledge the National Science Centre, Poland (NCN) for financial support (Project No. 2017/25/N/ST5/00766). References 1 S. Heinl, M. Scheer, Dalton Trans. 2014, 43, 2172-2179. 2 C. C. Cummins, Chem. Commun. 1998, 1777-1786. 3 J. V. Kourkine, D. S. Glueck, Inorg. Chem. 1997, 36, 5160-5164. 4 T.W. Graham, K. A. Udachin, A. J. Carty, Inorg. Chim. Acta., 2007, 360, 1376-1379. 5 M. Alonso, M. A. Alvarez, M. E. García, D. García-Vivó, M. A. Ruiz, Dalton Trans., 2014, 43, 16074- 16083.

Uppsala University, SWEDEN O4 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Intramolecular SEAr reaction of Phosphorous Compounds: mechanistic approaches

Olatz Larrañaga,a Carlos Romero-Nieto,b*Abel de Cózar.*a,c

aDepartamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Universidad del País Vasco and Donostia International Physics Center, P. K. 1072, 20018 San Sebastián - Donostia, Spain. b Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany c IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain. abel.decozar@ ehu.eus

Polyaromatic materials play a fundamental role in organic electronic applications such as field-effect transistors, light-emitting devices, solar cells and sensors.1 In this line, increasing research interest has been devoted to the integration of phosphorus rings into polyaromatic materials. Moreover, the most investigated phosphorus systems for materials applications are based on phospholes2 and phosphabenzenes (phosphininies) have been less studied despite their appealing properties on material sciences. In this communication we will present our results on the mechanism of the formation and optical properties of new phosphorous containing polyaromatic compounds3 (Scheme 1) by means of DFT framework.

Scheme 1 Acknowledgement The authors gratefully acknowledge the Spanish Ministry of Economy and Competitiveness (MINECO CTQ2013-45415P and CTQ2016-80375P). References 1 a) M. Bendikov, F. Wudl, D. F. Perepichka, Chem. Rev. 2004, 104, 4891-4946. b) A. Narita, X.-Y. Wang, X. Feng, K. Müllen, Chem. Soc. Rev. 2015, 44, 6616-6643. c) T. Zhang, D. Liu, Q. Wang, R. Wang, H. Renb, J. Li, J. Mater. Chem., 2011, 21, 12969-12976. d) C. B. Nielsen, S. Holliday, H.-Y. Chen, S. J. Cryer, I. McCulloch, Acc. Chem. Res. 2015, 48, 2803-2812. e) H. Dong, H. Zhu, Q. Meng, X. Gong, W. Hu, Chem. Soc. Rev. 2012, 41, 1754-1808. 2 M. P. Duffy, W. Delaunay, P.-A. Boui, M. Hissler, Chem. Soc. Rev., 2016, 45, 5296-5310. 3 a) C. Romero-Nieto, A. López-Andarias, C. Egler-Lucas, F. Gebert, J. P. Neus, O. Pilgram, Angew. Chem. Int. Ed., 2015, 54, 15872-15875. b) P. Hindenberg, A. López-Andarias, F. Rominger, A. de Cózar, C. Romero-Nieto, Chem. Eur. J. 2017, 23, 13919-13928. c) O. Larrañaga, C. Romero-Nieto, A. de Cózar, Chem. Eur. J. 2017, 23, 17487-17496.

Uppsala University, SWEDEN O5 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Green synthetic routes towards α-hydroxyphosphonates and derivatives

Zita Rádai*, Nóra Zsuzsa Kiss, Viktória Hodula, Réka Szabó, Zoltán Mucsi and György Keglevich

Department of Organic Chemistry and Technology, Budapest University of Technology and Economics. Budapest. Hungary. [email protected]

α-Hydroxyphosphonates have attracted great interest as bioactive organophosphorus species. A green method has been developed for the synthesis of α-hydroxyphosphonates by the addition of dialkyl phosphites to substituted benzaldehydes, in the presence of triethylamine as the catalyst, minimizing the use of volatile organic solvents [1]. The novelty of our method is the “one-pot” synthesis and crystallization step, eliminating the need for additional purification.

The reactions of α-hydroxyphosphonates may lead to valuable compounds. Their substitution with primary amines afforded the corresponding α-aminophosphonates (A) [2], while the catalytic hydrogenation of dibenzyl α-hydroxyphosphonates provided α-hydroxyphosphonic acids (B). The phosphorylation of the α hydroxy group with phosphinic chlorides led to a new family of α- hydroxyphosphonate derivatives (C). The rearrangement of α-hydroxyphosphonates to benzyl was investigated in the presence of bases (D).

Acknowledgements Z. Rádai is grateful for the fellowship provided by Chinoin–Sanofi Pharmaceuticals and Pro Progressio Foundation. N. Z. Kiss was supported by the New National Excellence Program of the Ministry of Human Capacities (ÚNKP-17-4-I-BME- 133). References 1 G. Keglevich, Z. Rádai, N. Z. Kiss, Green Process. Synth. 2017, 6, 197-201. 2 N. Z. Kiss, Z. Rádai, Z. Mucsi, G. Keglevich, Heteroat. Chem. 2016, 27, 260-268.

Uppsala University, SWEDEN O6 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Triazaphospholenium Tetrafluoroborate: A Phosphorus-Analogue of a 1,2,3-Triazole-Derived Carbene

Martin Papke ,a Lea Dettling,a Julian A. W. Sklorz, a Dénes Szieberth, b László Nyulászi b and Christian Müller a,*

aDepartment of Chemistry and Biochemistry, Freie Universität Berlin. Berlin. Germany; bDepartment of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics and MTA-BME. Budapest. Hungary. @ [email protected]

Since the pioneering work of Bertrand and Arduengo III, heteroatom-stabilized carbenes have emerged to an important and versatile class of compounds during the last decades. 1 Based on the highly flexible copper-catalyzed [3+2] cycloaddition reaction of acetylenes and organoazides, 1,2,3-triazolylidenes of type A have recently been developed as a new class of abnormal carbenes.2 These compounds play a significant role in carbene-chemistry, due to their modular synthesis and flexibility of metal insertion.

Inspired by the obvious analogy between 1,2,3-triazolylidenes and 1,2,3,4-triazaphospholenium salts of type B, we now started to investigate the synthesis, coordination chemistry and possible applications of such a phosphorus compound. 3 According to the principle of valence isoelectronicity, the corresponding phosphorus heterocycle represents the first formal phosphorus analogue of mesoionic carbenes (A).

In general 3H-1,2,3,4-triazaphosphole derivatives can be selectively alkylated with Meerwein´s reagent at the most nucleophilic nitrogen atom. Theoretical calculations revealed that the cation in triazaphospholenium tetrafluoroborate is an aromatic system with a high degree of π-conjugation. First investigations 2- showed that the cationic phosphorus heterocycle can stabilize a [Cu 2Br 4] dianion by formation of a neutral coordination compound with an unusual bonding situation between phosphorus and copper(I).

Acknowledgement Financial support by the Freie Universität Berlin and the DFG Research Training Network 1582 “Fluorine as a Key Element” is gratefully acknowledged.

References 1 a) A. Igau, H. Grützmacher, A. Baceiredo, G. Bertrand, J. Am. Chem. Soc. 1988 , 110 , 6463-6466; b) A. J. Arduengo, R. L. Harlow, M. Kline, J. Am. Chem . Soc . 1991 , 113 , 361-363. 2 P. Mathew, A. Neels, M. Albrecht, J. Am. Chem. Soc . 2008 , 130 , 13534-13535. 3 M. Papke, L. Dettling, J. A. W. Sklorz, D. Szieberth, L. Nyulászi, C. Müller, Angew. Chem. Int. Ed . 2017 , 56 , 16484-16489.

Uppsala University, SWEDEN O7 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Expanding the Pool of Phosphorus Rich Ferrocenophanes

Denis Kargin,a Stefan Isenberg,a Zsolt Kelemena and Rudolf Pietschniga,*

aUniversity of Kassel, Institute of Chemistry, Chemical Hybrid Materials, Kassel, Germany. [email protected]

[n]Ferrocenophanes (especially n=1) are attractive monomers for the ring opening polymerization (ROP) to ferrocenylene based phosphorus polymers.[1] The ring strain present in these type of molecules render them thermally unstable. Although, the tendency for thermal ROP is significantly reduced for n=2,3 the number of phosphorus containing ferrocenophanes with two or more phosphorus atoms in the bridge is rather small.[2-4] Due to their stereogenic properties the number of diastereomers increases with the number of phosphorus atoms in a chain, which can be reduced by embedding the chain into a cyclic ferrocenophane backbone.[3,4] We present a bundle of new phospha [n]ferrocenophanes incorporating different main group elements, various synthetic approaches and addressing different attributes including stereo-, tetrylene- and electrochemistry as well as radical generation and polymerization.

trans cis

Acknowledgement The authors gratefully acknowledge financial support by the DFG (PI 353/8-1 & 9-1), SFB 1319 (ELCH) and COST action CN 1302 (SIPs).

References [1] Pietschnig, Chem. Soc. Rev. 2016, 45, 5216; Manners, Angew. Chem. Int. Ed. 2007, 46, 5060. [2] Mizuta et al., J. Organomet. Chem. 2012, 713, 80; Dalton Trans. 2016, 45, 19034. [3] Pietschnig et al., Chem. Eur. J. 2017, 23, 10438; Dalton Trans. 2016, 45, 2180. [4] Pietschnig et al., Chem. Eur. J. 2009, 46, 12589.

Uppsala University, SWEDEN O8 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Lubricant Chemistry at the Interface of Surfaces Organophosphorus Additive Interactions in Engine Lubricant Formulations

M. Heeran,a J. C. Speelmanb and P. W. Dyera,*

a Department of Chemistry, Durham University, Durham, UK. b AkzoNobel Surface Chemistry, Deventer, NL. [email protected]

Friction modifiers R Anti-foam Anti- agents oxidants RO S OR N ZDDPs S R P Zn P S Viscosity RO S OR Dispersants improver ZDDP Friction Modifier Detergents

Zinc dialkyl/diaryl dithiophosphates (ZDDPs), Zn{S2P(OR)2}, are the most successful lubricant additives ever developed. They offer not only antioxidant, but also long-lasting anti-wear and extreme pressure properties. However, in modern crankcase engine lubricants, ZDDPs are used alongside a myriad of other additives, thereby creating the potential for both synergistic and/or antagonistic interactions in solution.1 The scientific understanding and consequences of any such interactions however, is an area that is significantly under-developed, and thus hinders the development of next- generation engine lubricant systems. The convergence of emission and fuel economy demands alongside tighter legislation,2 in particular, highlights the pressing need for a fundamental understanding of additive-additive interactions to enable the design and development of new lubricant package formulations, which meet the contradictory future demands of engine lubricants. Here, we expose the complex nature and impact of solution-phase interactions of ZDDPs with various amine-functional friction modifiers of commercial interest, or suitable model amine alternatives where applicable. For example, complexation can occur, which takes place through amine coordination to the zinc centre of ZDDP and is accompanied by a significant change in coordination behaviour of the associated dithiophosphate ligands, that in turn affects the degradation of the ZDDP moiety – a key feature in providing essential anti-wear properties. Acknowledgement The authors gratefully acknowledge AkzoNobel and the EPSRC CDT in Soft Matter and Functional Interfaces (Grant Ref. No. EP/L015536/1) for funding. References 1 H. Spikes, Tribol. Lett., 2004, 17, 469-489. 2 V. W. Wong and S. C. Tung, Friction, 2016, 4, 1-28.

Uppsala University, SWEDEN O9 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Dispersion forces in Frustrated Lewis pair chemistry Flip Holtrop and J. Chris Slootweg*

Main group chemistry & , Van ‘t Hoff Institute for Molecular Sciences, University of Amsterdam, Netherlands [email protected]

Frustrated Lewis pairs (FLPs) combine a Lewis acidic and Lewis basic site to activate small molecules granting access to interesting main group chemistry and catalysis. For example, FLPs are able to heterolytically cleave dihydrogen allowing for their use as organocatalysts in hydrogenation reactions.1 In addition, FLPs can activate a variety of small molecules illustrating their potential for further organocatalytic applications. This unique reactivity is the result of synergistic interaction of a Lewis acid and base with the substrate. To achieve this, the Lewis acid and base are proposed to preform a van der Waals complex creating a reactive pocket in which a small can subsequently be activated.2 This highlights the importance of dispersion forces in frustrated Lewis pair chemistry.

This work explores both the van der Waals forces in Lewis adduct and frustrated Lewis pair formation, and the synthesis of FLP van der Waals complexes to elucidate the mechanism of small molecule activation within their reactive pockets.

References 1 a D. Stephan, G. Erker, Angew. Chem. Int. Ed. 2015, 54, 6400 b D. Stephan, Science 2016, 354, 1248 2 a G. Skara, F. De Vleeschouwer, P. Geerlings, F. De Proft, B. Pinter, Scientific Reports 2017, 7, 16024 b L. Rocchigiani, G. Ciancaleoni, C. Zuccaccia, A. Macchioni, J. Am. Chem. Soc. 2014, 136, 112

Uppsala University, SWEDEN O10 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Pt(0)-catalysed Hydrophosphination as a Route to Diphosphine Ligands for SPECT Imaging

Ailis Chadwick,a, b Martin Heckenast,a Paul G. Pringle*,a James Race,a Michelle T. Ma,b Philip J. Blower.b a School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, UK b King's College London, Division of Imaging Sciences and Biomedical Engineering, St Thomas' Hospital, London SE1 7EH, UK [email protected]

Hydrophosphination, the addition of a P‒H bond across a multiple bond, may be achieved by a variety of routes including acid- or base-catalysis, and radical initiation.1 Of the large number of methods available, transition metal-catalysis provides the greatest potential to combine high atom‒efficiency with selectivity to create new phosphorus‒carbon bonds.2

Platinum(0)‒catalysed hydrophosphination of activated offers access to functionalized phosphines that have proved useful as ligands for homogeneous catalysis.3 This process was first reported in 1990 when it was shown that addition of PH3 to acrylonitrile was catalysed by a platinum(0) complex.4

Investigations into the mechanism of platinum(0)‒catalysed hydrophosphination have focused on the synthesis of monophosphines.5 Surprisingly, despite the possibility of catalyst poisoning by substrate chelation, functionalized diphosphines can also be prepared via this method.6 Here we demonstrate the efficient and selective hydrophosphination of unsymmetrical diphosphine 1 to give 2 and related diphos ligands and investigate the mechanism of these transformations.

The coordination chemistry of 2 with Pt(II), Tc(V) and Re(V) has been explored for application to SPECT imaging and radiotherapy.

References (1) Costa, E.; Pringle, P. G.; Smith, M. B.; Worboys, K. J. Chem. Soc., Dalton Trans. 1997, 4277. (2) Espinal-Viguri, M.; King, A. K.; Lowe, J. P.; Mahon, M. H.; Webster, R. L. ACS Catal. 2016, 6, 7892. (3) Wicht, D. K.; Kourkine, I. V.; Lew, B. M.; Nthenge, J. M.; Glueck, D. S. J. Am. Chem. Soc. 1997, 119, 5039. (4) Pringle, P. G.; Smith, M. B. J. Chem. Soc. Chem. Commun. 1990, 1701. (5) Scriban, C.; Kovacik, I.; Glueck, D. S. Organometallics 2005, 24, 4871. (6) Kovacik, I.; Scriban, C.; Glueck, D. S. Organometallics 2006, 25, 536.

Uppsala University, SWEDEN O11 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

A P-H Functionalized Al/P Based Frustrated Lewis Pair - Substrate Activation and Hydrophosphination

Lukas Keweloha, Werner Uhla

aInstitut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität, Münster, Germany. [email protected]

Hydroalumination of the secondary alkynylphosphine 1 with the bulky hydride Bis2Al-H affords the P-H functionalized FLP 21. The P-H group represents a new approach in FLP chemistry with an additional active moiety. 2 shows the dipolar substrate complexation similar to conventional FLPs followed by hydrophosphination of various activated substrates2,3.

Many functional groups with unsaturated CN bonds such as nitriles (3), azides (4), cyanates, isocyanates and carbodiimides have been reduced by H shift to N. Diphenyl-cyclopropenon (5) undergoes a ring opening reaction with P-H addition of the strained CC single bond. A kinetically hindered hydrogen migration, observed at a keteneimine (6), is facilitated by DABCO as proton transfer reactant, here by C-H bond formation (7). The products are formed in highly selective reactions.

References

1 L. Keweloh, H. Klöcker, E.-U. Würthwein, W. Uhl, Angew. Chem. 2016, 55, 3212. 2 W. Uhl, L. Keweloh, A. Hepp, F. Stegemann, M. Layh, K. Bergander, Z. Anorg. Allg. Chem. 2017, 643, 1978. 3 W. Uhl, J. Backs, A. Hepp, L. Keweloh, M. Layh, D. Pleschka, J. Possart, Z. Naturforsch. 2017, 72b, 821.

Uppsala University, SWEDEN O12 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

A simple route to phosphinecarboxamides: reactivity of the PCO ̅ anion towards amino acids and hydrazine

Erica N. Faria,a Andrew R. Jupp,a Jose M. Goicoecheaa,*

aDepartment of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, OX1 3TA. Oxford. United Kingdom. [email protected]

The 2-phosphaethynolate anion (PCO–, a heavier analogue of cyanate), was first reported in 1992 as a lithium salt by Becker and co-workers.1 However, given the inherent reactivity of this salt, this novel anion was not extensively studied. Recently, the synthesis of more stable salts has been reported by using heavier alkali metal counter cations.2–5

In 1828, Wöhler reported the synthesis of urea by the reaction between silver cyanate and ammonium chloride. Inspired by this seminal study, we explored the reactivity of PCO– towards ammonium salts. This research resulted in the synthesis of phosphinecarboxamide (PH2C(O)NH2), a heavier analogue of urea, which is both air and moisture stable, unlike most primary phosphines.6, 7

Reactions between PCO– and amino acids afforded sodium salts of functionalized amino acids which can readly be protonated (see figure). Reactions involving hydrazine hydrochlorides can similarly be used to afford novel neutral phosphines.

Acknowledgement The authors gratefully acknowledge the Conselho Nacional Desenvolvimento Científico e Tecnológico (CNPq) and the EPRSC for financial support. References 1 G. Becker, W. Schwarz, N. Seidler, M. Westerhausen. Z. Anorg. Allg. Chem. 1992, 612 (6), 72–82. 2 F. F. Puschmann, D. Stein, D. Heift,C. Hendriksen, Z. A. Gal, H.F. Grützmacher, H. Grützmacher. Angew. Chem. Int.Ed. 2011, 50 (36), 8420–8423. 3 A. R. Jupp, J. M. Goicoechea. Angew. Chem. Int. Ed. 2013, 52 (38), 10064–10067. 4 D. Heift, Z. Benko, H. Grutzmacher. Dalton Trans. 2014, 43 (2), 831–840. 5 Z. J. Quan, X. C. Wang. Org. Chem. Front. 2014, 1 (9), 1128–1131. 6 A. R. Jupp, J. M. Goicoechea. J. Am. Chem. Soc. 2013, 135 (51), 19131–19134. 7 C. A. Tsipis, P. A. Karipidis. J. Am. Chem. Soc. 2003, 125 (8), 2307–2318.

Uppsala University, SWEDEN O13 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis and reactions of novel 1,4-diphosphinines

Imtiaz Begum,a Z. Kelemen b, L. Nyulászi b* and R. Streubel c,*

aUniversity of Bonn, Institute of Inorganic Chemistry, Gerhard-Domagk-Str.1, 53121 Bonn, Germany. bBudapest University of Technology and Economics [email protected]

Phosphinines such as I represent a landmark discovery in phosphorus chemistry[1] which has stimu- lated intensive studies on synthesis and ligand properties. But it also spurred a rapid development in heterocyclic and low-coordinate phosphorus chemistry. However, only the monocyclic example of a 1,4-diphosphinine II[2] was reported for a long time, but in 2017 we described a route to III.[3]

Scheme 1. Previously reported phosphinine I and 1,4-diphosphinines II,III.

Herein, synthesis of thiazole-2-thione-based tricyclic 1,4-diphosphinine 2 using 1 as precursor is des- cribed. Reactivity studies reveal a rich and versatile chemistry of 2 including such reactions with nucleophiles and electrophiles to give 3 as well as concerted reactions to provide 1,4-diphospha- barellene 4.[4] This and more will be presented during this lecture.

Scheme 2. Synthesis of 1,4-diphosphinine 2 and its reactions with a nucleophile electrophile pair to give 3 and concerted reactions to provide 1,4-diphosphabarellene 4.

Acknowledgement I. Begum is greatful to DAAD for a PhD fellowship and the COST action CM1302 (SIPs) for financial support. References 1 Märkl, Angew. Chem. Int. Ed. Engl, 1966, 5, 846. 2 Y. Kobayashi, J. Kumadaki, A. Ohsawa, W. Hamana, Tetrahedron Lett, 1976, 3715. 3 A. Koner, G. Pfeifer, Z. Kelemen, G. Schnakenburg, L. Nyulászi, T. Sasamori, R. Streubel, Angew. Chem. Int. Ed, 2017, 56, 9231. 4 I. Begum, Z. Kelemen, G. Schnakenburg, L. Nyulászi, R. Streubel, submitted, 2018.

Uppsala University, SWEDEN O14 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Nucleophilic Activation of Hexafluoride: Metal-free, Selective Degradation by Phosphines

Florenz Buß, Christian Mück-Lichtenfeld, Paul Mehlmann and Fabian Dielmann*

Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster. Germany. @ [email protected]

The development of new methods for the chemical activation of inert greenhouse gases such as sulfur hexafluoride (SF6), carbon dioxide (CO2) and nitrous oxide (N2O) not only is of current environmental interest, but also offers new opportunities for their efficient use as feedstock in organic synthesis. Regarding SF6, examples for the mild chemical activation are rare and metal-free procedures for the complete degradation of SF6 have not yet been identified. Our strategy to activate SF6 under mild conditions is based on the use of electron-rich phosphines with imidazolin-2- ylidenamino substitutents (IAPs). These phosphines are more basic than alkyl- and aryl- phosphines.[1] NMR studies, X-ray crystallographic studies, DFT calculations as well as a scalable [2] one-pot procedure for the complete degradation of SF6 are depicted in detail on the poster.

Nucleophilic activation and degradation of SF6 by electron-rich phosphines.

Acknowledgement The authors gratefully acknowledge financial support from the DFG (IRTG 2027, SFB 858). References 1 a) F. Buß, P. Mehlmann, C. Mück-Lichtenfeld, K. Bergander, J. Am. Chem. Soc. 2016, 138, 1840. b) P. Mehlmann, C. Mück-Lichtenfeld, T. Tan, F. Dielmann, Chem. Eur. J. 2017, 23, 5929. 2 a) F. Buß, C. Mück-Lichtenfeld, P. Mehlmann, F. Dielmann Angew. Chem. Int. Ed. 2018, DOI: 10.1002/anie.201713206R2. b) F. Buß and F. Dielmann; German patent application DE 10 2017 124 415.8

Uppsala University, SWEDEN O15 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Self-assembled Networks of Nano-Sized Spherical Supramolecules 5 Coordination Chemistry of [Cp*Fe(η -P5)], AgSbF6 and flexible Dinitriles

Barbara Krämer, Manfred Scheer

Institute of Inorganic Chemistry, University of Regensburg. Regensburg. Germany. [email protected]

5 Over the years the Pn ligand complex [Cp*Fe(η -P5)] has been established as a versatile building block in coordination chemistry driven by self-assembly processes. With coinage metal salts 1D and 2D[1] polymeric compounds could be characterized, as well as nano-sized spherical supramolecules[2] are accessible via a template-controlled assembly.

By applying appropriate conditions and adding fully flexible dinitrile linker molecules NC(CH2)xCN 5 (x = 5-10) to the building blocks [Cp*Fe(η -P5)] and AgSbF6, polymeric networks are formed. While the shorter linker molecules (x = 5, 6) lead to 1D, 2D and 3D three-component polymeric structures, the longer linker with x ≥ 7 open the door to a unprecedented class of compounds (Scheme 1). Thus, several entirely self-assembled 3D networks of connected spherical supramolecules could be characterized as its first representatives. Moreover, the nano-sized spheres exhibit inner voids to host smaller molecules.

5 Scheme 1: Detail of a fcc type 3D network of connected spheres consisting of [Cp*Fe( -P5)], AgSbF6 and a flexible dinitrile. [Cp*Fe] units, anions and encapsulated molecules are not depicted.

Acknowledgement The authors gratefully thank the European Research Council (ERC) for the SELFPHOS AdG-339072 project. References 1 a) M. Scheer, L. J. Gregoriades, A. V. Virovets, W. Kunz, R. Neueder, I. Krossing, Angew. Chem. Int. Ed. 2006, 45, 5689-5693; b) F. Dielmann, A. Schindler, S. Scheuermayer, J. Bai, R. Merkle, M. Zabel, A. V. Virovets, E. V. Peresypkina, G. Brunklaus, H. Eckert, M. Scheer, Chem. Eur. J. 2012, 18, 1168-1179. 2 a) J. Bai, A. V. Virovets, M. Scheer, Science 2003, 300, 781-783; b) M. Scheer, A. Schindler, R. Merkle, B. P. Johnson, M. Linseis, R. Winter, C. E. Anson, A. V. Virovets, J. Am. Chem. Soc. 2007, 129, 13386- 13387; c) A. Schindler, C. Heindl, G. Balazs, C. Groeger, A. V. Virovets, E. V. Peresypkina, M. Scheer, Chem. Eur. J. 2012, 18, 829-835; d) C. Schwarzmaier, A. Schindler, C. Heindl, S. Scheuermayer, E. V. Peresypkina, A. V. Virovets, M. Neumeier, R. Gschwind, M. Scheer, Angew. Chem. Int. Ed. 2013, 52, 10896-10899.

Uppsala University, SWEDEN O16 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

2D black phosphorus decorated with palladium nanoparticles. Synthesis, characterization and catalytic applications

Matteo Vanni,a Manuel Serrano-Ruiz,a Francesca Telesio,b Stefan Heun,b Maria Caporali,a Maurizio Peruzzinia a CNR ICCOM, Istituto di Chimica dei Composti Organometallici, Via Madonna del Piano, 10, 50019 Sesto Fiorentino (Italy). b NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro, 12, 56121 Pisa (Italy). [email protected]

Black phosphorus, firstly prepared by physicist Percy Bridgman in 1914, was recently rediscovered after the report of its mechanical exfoliation.(1) The resulting bidimensional material (2D BP), a phosphorus-based counterpart of graphene, aroused tremendous interest given its semiconductor properties with a layer dependent band gap, ranging from 0.3 eV (bulk material) to 2.0 eV (monolayer). However, a major drawback limiting the applications of 2D BP is its instability toward the mutual effect of , water and light. In our labs, 2D BP was prepared by sonochemically assisted solvent exfoliation of bulk black phosphorus under inert atmosphere.(2) We speculated that given the formal presence of a lone pair on each P-atom, 2D BP would be an excellent material to anchor metal nanoparticles(3) and turned our attention on palladium. The growth of palladium nanoparticles was performed in situ by reduction of a Pd(II) salt previously impregnated on the surface of 2D BP. TEM observation of the resulting material (Pd@BP) showed a good covering of 2D BP flakes by Pd nanoparticles. Pd@BP was then tested as catalyst in the hydrogenation of halonitroarenes to haloanilines, a reaction often affected by dehalogenation byproducts. Higher selectivity compared to known heterogeneous catalysts based on supported Pd nanoparticles was observed, pointing out the relevant role of 2D BP as support.

Acknowledgement This work was supported by an ERC Advanced Grant PHOSFUN "Phosphorene functionalization: a new platform for advanced multifunctional materials” (Grant Agreement No. 670173) to M. P.

References 1 L. Li, Y. Yu, G. J. Ye, Q. Je, X. Ou, H. Wu, D. Feng, X. H. Chen, Y. Zhang, Nat. Nanotech. 2014, 9, 372. 2 M. Serrano-Ruiz, M. Caporali, A. Ienco, V. Piazza, S. Heun, M. Peruzzini, Adv. Mater. Interfaces 2016, 3, 1500441. 3 M. Caporali, M. Serrano-Ruiz, F. Telesio, S. Heun, G. Nicotra, C. Spinella, M. Peruzzini, Chem. Commun., 2017, 53, 10946-10949.

Uppsala University, SWEDEN O17 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis and Reactivity of 2 2 2 Nickel-Stabilised µ :η ,η -P2, As2 and PAs Units

Gabriele Hierlmeier,a Alexander Hinz,b Robert Wolfa,* and Jose Manuel Goicoecheab,*

aUniversity of Regensburg, Institute of Inorganic Chemistry, 93040 Regensburg, Germany. b Department of Chemistry, University of Oxford, Department of Chemistry, 12 Mansfield Road, OX1 3TA Oxford (UK), United Kingdom. [email protected]

Despite still being regarded as rare, the chemistry of nickel compounds in the +1 oxidation state has undergone significant development over the last decades.[1] At the same time, the reactivity of the heavier group 15 cyanate analogue 2-phosphaethynolate PCO− has also rapidly evolved due to the stability and facile preparation of its sodium salt NaPCO.[2] This small anion has been shown to undergo salt metathesis reactions with metal halides which led to a variety of unprecedented phosphorus-containing compounds.[3] Nickel(I) complexes of the type [CpNi(NHC)] (NHC = IMes, IPr)[4] react in salt metathesis reactions with the heavier group 15 cyanate analogues NaPCO and NaAsCO, giving rise to [NiPn(CO)(NHC)]2 2:2 complexes (Pn = P, As) with μ,η -Pn2 units. Intermediates in these reactions such as phosphinidyne complexes and phosphaketenes were isolated and characterised. Moreover, the new [NiPn(CO)(IMes)]2 complexes release white phosphorus (P4) and elemental arsenic via Pn2 type intermediates upon reaction with CO.[5]

References 1 C.-Y. Lin, P. P. Power, Chem. Soc. Rev. 2017, 46, 5397. 2 a) F. F. Puschmann, D. Stein, D. Heift, C. Hendriksen, Z. A. Gal, H.-F. Grützmacher, H. Grützmacher, Angew. Chem. Int. Ed. 2011, 50, 8420; b) D. Heift, Z. Benko, H. Grützmacher, Dalton trans. 2014, 43, 831; c) A. Hinz, J. M. Goicoechea, Angew. Chem. Int. Ed. 2016, 55, 8536. 3 a) L. Liu, D. A. Ruiz, F. Dahcheh, G. Bertrand, R. Suter, A. M. Tondreau, H. Grützmacher, Chem. Sci. 2016, 7, 2335; b) L. N. Grant, B. Pinter, B. C. Manor, R. Suter, H. Grützmacher, D. J. Mindiola, Chem. Eur. J. 2017, 23, 6272; c) C. Camp, N. Settineri, J. Lefèvre, A. R. Jupp, J. M. Goicoechea, L. Maron, J. Arnold, Chem. Sci. 2015, 6, 6379. 4 a) S. Pelties, D. Herrmann, B. de Bruin, F. Hartl, R. Wolf, Chem. Commun. 2014, 50, 7014; b) S. Pelties, R. Wolf, Organometallics 2016, 35, 2722; c) S. Pelties, A. W. Ehlers, R. Wolf, Chem. Commun. 2016, 52, 6601. 5 G. Hierlmeier, A. Hinz, R. Wolf, J. M. Goicoechea, Angew. Chem. Int. Ed. 2018, 57, 431; Angew. Chem. 2018, 130, 439.

Uppsala University, SWEDEN O18 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis of contorted Polycyclic Aromatic Hydrocarbons by cycloadditions from polycyclic phospholes

a, a b b Réka Mokrai,a, b Rózsa Szűcs, b Pierre-Antoine Bouit, László Nyulászi, Zoltán Benkő, and Muriel Hisslera,* a Univ Rennes, CNRS, ISCR – UMR 6226, F-35000 Rennes, France; b Inorganic and Analytical Chemisrty Department, Budapest University of Technology and Economics. Budapest. Hungary. @ [email protected]

Polycyclic Aromatic Hydrocarbons (PAHs) are important experimental and theoretical objects due to their unique electronic properties making them appealing for applications in molecular electronics such as organic solar cells and field effect transistors.a-c Their physical properties can be modified by embedding heteroatoms into the sp2 backbone. For example, we synthesized P-containing PAHs and demonstrated that the chemical modifications performed at the P-atom such as complexation or oxidation, had a significant influence on the optical properties of the molecules.d-f During the aromaticity studies of P-containing PAHs, we have established that modification of the local aromaticity of the five-membered ring (by chemical modifications of the phosphorus atom) has a significant impact on the local aromaticities of the other rings. It has been shown both experimentally and theoretically that the Diels-Alder cycloadditiong of the P-embedded PAHs proceeds at the heterocyclic rings that exhibit the lowest aromaticity in the π-system. Then, these reactions were used to synthesize non-planar all- carbon PAHs. The mechanism of this novel approach to PAHs has been studied experimentally and computationally (DFT calculations). The new PAHs are characterized by NMR spectroscopy and single crystal X-ray diffraction. The optical and electrochemical properties have been studied and complemented by DFT calculations. In conclusion, the physical properties of these compounds make them valuable building blocks for the development of active molecules in devices.

Acknowledgement The authors gratefully acknowledge the Campus France, Tempus Public Foundation, Pro Progressio Alapítvány, Hungarian-French TéT Program TÉT_16-1- 2016-0128. References a) M. D. Watson, A. Fechtenkötter, K. Müllen, Chem. Rev. 2001, 101, 1267-1300. b) W. Pisula, X. Feng, K. Müllen, Chem. Matter. 2011, 23, 554-567. c) J. Wu, W. Pisula, K. Müllen, Chem. Rev. 2007, 107, 718-747. d) P-A. Bouit, A. Escande, R. Szűcs, D. Szieberth, C. Lescop, L. Nyulászi, M. Hissler, R. Réau J. Am. Chem. Soc. 2012, 134, 6524-6527. e) R. Szűcs, P-A. Bouit, L. Nyulászi, M. Hissler ChemPhysChem. 2017, 18, 2618-2630. f) F. Riobé, R. Szűcs, C. Lescop, R. Réau, L. Nyulászi, P-A. Bouit, M. Hissler Organometallics 2017, 36, 2502- 25011.

g) F. Mathey, F. Mercier, C. Charrier J. Am. Chem. Soc. 1981, 103, 4595-4597.

Uppsala University, SWEDEN O19 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

BN and BP Analogues of Poly(p-phenylene vinylene) (PPV)

Merian Crumbach, Thomas Lorenz, Holger Helten*

Institute of Inorganic Chemistry, RWTH Aachen University, Aachen, Germany [email protected]

Substitution of selected CC units by their isoelectronic and isosteric BN units in π-conjugated organic systems (BN/CC isosterism) has emerged as a viable strategy to produce novel materials with structural similarities to their all-carbon congeners, but in many cases fundamentally altered electronic features.1 While this concept has been successfully applied to mono- and polycyclic aromatic hydrocarbons, first examples have just demonstrated its applicability to polymer chemistry.2-4 The incorporation of BP units, on the other hand, which are valence isoelectronic with BN and CC, into unsaturated organic compounds has been scarcely studied, though the potential of the resulting BCP hybrid materials for electronic applications has been recognized quite recently.5 Main chain-conjugated polymers featuring BP fragments in the backbone are unknown so far. Recently, we have introduced / exchange polycondensation as a novel polymerization method.3 Herein, the synthesis and characterization of the first poly(p-phenylene iminoborane) (BN- PPV) is presented.4 This novel inorganic–organic hybrid polymer can be regarded as a BN analogue of the well-known poly(p-phenylene vinylene) (PPV). Photophysical studies, supported by TD-DFT calculations, as well as molecular structures of model oligomers will also be discussed. Furthermore, our recent advances in the preparation of BP analogues of PPV (BP-PPV) will be presented.6

Acknowledgements The authors gratefully acknowledge the COST action CM1302 (SIPs), and the German Research Foundation (DFG) for funding through the Emmy Noether Programme and the Research Grant HE 6171/4-1.

References 1 M. J. D. Bosdet, W. Piers, Can. J. Chem. 2009, 87, 8-29. 2 a) A. W. Baggett, F. Guo, B. Li, S.-Y. Liu, F. Jäkle, Angew. Chem. Int. Ed. 2015, 54, 11191-11195; b) X.-Y. Wang, F.- D. Zhuang, J.-Y. Wang, J. Pei, Chem. Commun. 2015, 51, 17532-17535. 3 a) T. Lorenz, A. Lik, F. A. Plamper, H. Helten, Angew. Chem. Int. Ed. 2016, 55, 7236-7241; b) O. Ayhan, T. Eckert, F. A. Plamper, H. Helten, Angew. Chem. Int. Ed. 2016, 55, 13321-13325; c) H. Helten, Chem. Eur. J. 2016, 22, 12972- 12982; d) A. Lik, L. Fritze, L. Müller, H. Helten, J. Am. Chem. Soc. 2017, 139, 5692-5695; e) N. A. Riensch, A. Deniz, S. Kühl, L. Müller, A. Adams, A. Pich, H. Helten, Polym. Chem. 2017, 8, 5264-5268; f) O. Ayhan, N. A. Riensch, C. Glasmacher, H. Helten, Chem. Eur. J. 2018, 10.1002/chem.201705913. 4 T. Lorenz, M. Crumbach, T. Eckert, A. Lik, H. Helten, Angew. Chem. Int. Ed. 2017, 56, 2780-2784. 5 a) A. Tsurusaki, T. Sasamori, A. Wakamiya, S. Yamaguchi, K. Nagura, S. Irle, N. Tokitoh, Angew. Chem. Int. Ed. 2011, 50, 10940-10943; b) J. H. Barnard, P. A. Brown, K. L. Shuford, C. D. Martin, Angew. Chem. Int. Ed. 2015, 54, 12083– 12086; c) J. A. Bailey, M. F. Haddow, P. G. Pringle, Chem. Commun. 2014, 50, 1432–1434; d) A. N. Price, G. S. Nichol, M. J. Cowley, Angew. Chem. Int. Ed. 2017, 56, 9953–9957. 6 M. Crumbach, T. Lorenz, H. Helten, manuscript in preparation.

Uppsala University, SWEDEN O20 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Oxidative P−P Bond Addition to Cobalt(−I)

P. Coburger,a S. Demeshko,b , C. Rödl,c R. Wolfc and E. Hey-Hawkinsa,* a Leipzig University, Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Johannisallee 29, D-04103 Leipzig. b Georg-August-Universität Göttingen, Faculty of Chemistry, Tammannstraße 4, D-37077 Göttingen. c Regensburg University, Faculty of Chemistry and Pharmacy, Universitätsstraße 31, D-93053 Regensburg @ [email protected]

Homoleptic tetrahedral low-spin complexes of first-row transition metals are rare due to the weak 1 t 2 ligand-field splitting of classic ligands. Examples like [Co(norbornyl)4] or [Mn(N=C Bu2)4] require high oxidation states of the metal (+4) and strong σ-donor ligands, like alkyl groups, or strong π- donating and π-accepting ligands, like ketimides. Here, we present the synthesis and characterisation of a diamagnetic homoleptic cobalt- bis(phosphanido) complex (1) (Figure 1), featuring cobalt in the oxidation state +3.3

Figure 1: Section of the one-dimensional structure of 1 in the solid state with ellipsoids drawn at 50% probability level. Hydrogen atoms (other than the CH and BH groups involved in interactions) have been ommitted for clarity. tert-Butyl groups have been drawn as wireframes for clarity.

Acknowledgement The authors gratefully acknowledge the COST Action CM1302 (SIPs). Financial support by the Studienstiftung des deutschen Volkes (doctoral fellowship to P.C.) and the graduate school BuildMoNa (Leipzig University) is gratefully acknowledged. References 1 E. K. Byrne, D. S. Richeson, K. H. Theopold, J. Chem. Soc., Chem. Commun. 1986, 1491-1492. 2 R. A. Lewis, G. Wu, T. W. Hayton, Inorg. Chem. 2011, 50, 4660-4668. 3 P. Coburger, S. Demeshko, C. Rödl, E. Hey-Hawkins, R. Wolf, Angew. Chem. Int. Ed. 2017, 56, 15871-15875; Angew. Chem. 2017, 129, 16087-16091.

Uppsala University, SWEDEN O21 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Metalated diaminophosphine-boranes: functionalized P-nucleophiles

M. Bluma, T. Dunaja, J. Kapplera, C. Feila, W. Freyb, S. H. Schlindweina and D. Gudata

aInstitut für Anorganische Chemie, bInstitut für Organische Chemie, Universität Stuttgart, Stuttgart, Germany. Email: [email protected]

Formation of phosphorus-element bonds by reaction of a P-nucleophile with a suitable electrophile is of great interest in organoelement chemistry and alkaline metal phosphanides[1] derived from secondary alkyl, aryl or trimethylsilyl phosphines have become important synthetic tools. In contrast, examples of P-nucleophiles with electronegative substituents like amino-groups are confined to a single report by Knochel et al. who postulated that the reductive coupling of a diamino- chlorophosphine-borane with organic electrophiles proceeds via a transient metalated diaminophosphine-borane.[2] Even if no direct evidence for the intermediate was obtained, species of this type could be interesting synthons for molecular chemistry. Herein, we present an alternative pathway for the generation of lithiated diaminophosphine-boranes. Both the initial products and their transmetalation products could be characterized spectroscopically or structurally for the first time.[3] Finally, we also report on metathesis reactions with organoelement electrophiles to afford new multifunctional phosphine-boranes.

Figure 1: Functionalization of a diaminophosphine-borane. M = Li, K; E = SiMe2.

Acknowledgement The authors gratefully thank the bwHPC-C5 project of Baden-Württemberg for providing high performance computing clusters and the University of Stuttgart for financial support. References [1] K. Issleib, A. Tzschach , Chem. Ber., 1959, 92, 1118-1126. [2] A. Longeau, P. Knochel, Tetr. Let., 1996, 37, 6099-6102. [3] M. Blum, J. Kappler, S. H. Schlindwein, M. Nieger, D. Gudat, DaltonTrans. , 2018, 47, 112-119.

Uppsala University, SWEDEN O22 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

An Organocatalytic Approach to P-Stereogenicity

Martin Ó Fearraigha and Eoghan McGarriglea*

aSchool of Chemistry, Universtiy College Dublin. Dublin. Ireland. @ [email protected]

P-stereogenic molecules have found applications as ligands, catalysts and as biologically active molecules.[1] However routes for their asymmetric synthesis are far less numerous than their carbon analogues. To enable their full potential to be realized new methods need to be developed. These should be catalytic asymmetric methods and should start from readily available, cheap phosphorus- containing compounds. They must be efficient in their use of phosphorus – classified as an endangered element.[2]

Chiral organocatalysts containing thiourea/urea feature prominently in asymmetric synthesis and have been explored as excellent alternatives to transition-metal catalysts for their cost and operational simplicity. These catalysts have delivered high selectivities, proposed to proceed via anion abstraction binding or hydrogen bonding modes of action.[3] We aim to exploit this anion abstraction/binding motif of chiral thiourea/urea catalysts to render enantiopure compounds from readily available racemic or prochiral P-containing starting materials.

Acknowledgement The authors gratefully acknowledge the Irish Research Council (GOIPG/2014/528). References 1 a) S. Connon, Angew. Chem. Int. Ed. 2006, 45, 3909-3912. b) W. Tang, X. Zhang, Chem. Rev. 2003, 103, 3029- 3070. c) G. Birkus, R. Wang, X. Liu, N. Kutty, H. MacArthur, T. Cihlar, C. Gibbs, S. Swaminathan, W. Lee, M. McDermott, Antimicrob. Agents Chemother. 2007, 51, 543-550. 2 O. Kolodiazhnyi, In Asymmetric Synthesis in Organophosphorous Chemisrty; Synthetic Methods, Catalysis and Applications, 1st ed.; Wiley-VCH Verlag GmbH & Co. KGaA: Weinheim, Germany, 2017; Chapter 2. 3 a) K. Brak, E. Jacobsen, Angew. Chem. Int. Ed. 2013, 52, 534-561. b) N. Mittal, K. Lippert C. Kanta De, E. Klauber, T. Emge, P. Screiner, D. Seidel, J. Am. Chem.Soc. 2005, 137, 5748-5758.

Uppsala University, SWEDEN O23 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Reductive one-pot coupling of two aldehydes to unsymmetric E-alkenes via phosphaalkene and subsequent phosphinate intermediates

Juri Maia, Sascha Otta.

aUppsala University, Department of Chemistry, Ångström laboratory, 75120 Uppsala, Sweden [email protected]

The structural motif of C=C double bonds in nature and commodity chemicals – such as plastics, pigments, drugs or lipids and vitamins – is omnipresent. Thus, the development of new methodologies for the preparation of C=C -containing compounds from inexpensive starting materials is of great importance for organic synthetic chemistry. Here, we present a facile stereoselective P-mediated one-pot synthesis of unsymmetrically disubstituted E-alkenes from two different aldehydes.[1] The selectivity for the formation of E-alkenes is achieved by a sequential ionic mechanism. In the first step a phosphanylphosphonate[2] reagent 1 reacts with the first aldehyde to form a phosphaalkene intermediate 2 (Scheme 1). In this phosphaalkene the polarity of the carbonyl carbon has been reversed from δ+ to δ-, and the electrophilic phosphorus center in 2 can be activated by an alkoxide to afford intermediate 4. Oxidation of 4 leads to a phosphinate intermediate 5 which reacts under basic conditions with the second aldehyde to yield the olefinic product. By having electron withdrawing substituents R1 in the first aldehyde and electron donating groups as R2, E-stilbenes with a push-pull structural motif are easily accessible from simple aromatic aldehydes.[3]

Scheme 1: General reaction sequence for the reductive one-pot coupling. In comparison to the McMurry coupling[4], this new one-pot reaction proceeds under mild reaction conditions at room temperature and is free of transition metals. Moreover, it gives access to the formation of exclusively E- products with an unsymmetrical substitution pattern in good overall yields.

References [1] K. Esfandiarfard, J. Mai, S. Ott, J. Am. Chem. Soc., 2017, 139, 2940-2943. [2] K. Esfandiarfard, A.I. Arkhypchuk, A. Orthaber, S. Ott, Dalton Trans. 2016, 45, 2201-2207. [3] J. Mai, S. Ott, manuscript in preparation. [4] J. E. McMurry, Chem. Rev. 1989, 89, 1513-1524.

Uppsala University, SWEDEN O24 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Computational study on substituted phosphorus ylides

Dániel Buzsáki, Tamara Teski, László Nyulászi

Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics H-1111 Budapest Szt. Gellert ter 4, Hungary e-mail: [email protected]

Phosphorus ylides are well-known as key intermediates in Wittig reactions.[1,2] To describe their bonding, two canonical structures were considered: the double-bonded ylide and the zwitterionic ylene [3] form (Scheme 1a). The ylides HX2P=CY2 generally rearrange to their isomer, the [4] thermodynamically more stable phosphane X2P–CY2H via proton shift. Accordingly, no H-ylides were able to form with the exception of some kinetically hindered cases.[5] However, the smallest ylide [4] (H3P=CH2) was detected in gas phase in high vacuum conditions, and its stability was explained by the high monomolecular isomeration barrier (34 kcal/mol).[2] The ylide can be relatively stabilized with respect to the phosphane by σ-donating and π-withdrawing substituents. The bonding and structural properties of substituted phosphorus ylides were deeply investigated theoretically with DFT methods. The thermodynamical stability of these compounds were determined in comparison to their phosphane isomers. Nevertheless, we could not find any HX2P=CY2 type of ylides which were more stable than its phosphane isomer. Furthermore, here we present the bimolecular mechanism, which can propose a low barrier alternative compared to the monomolecular mechanism, thus can explain the common isomerization of the ylide.

Scheme 1 a) Different canonical structures of the ylides, b) Considered proton transfer mechanisms in this work

Acknowledgement Financial support from NKFIH OTKA NN 113772, and the EU COST network CM 1302 “Smart Inorganic Polymers” is gratefully acknowledged.

References 1 G. Wittig, Science, 1980, 21, 500. 2 O. I. Kolodiazhnyi, Phosphorus ylides, WILEY-VCH Verlag, 1999. 3 H. J. Bestmann; A. J. Kos; K. Witzgall, P. v. R. Schleyer, J. Chem. Ber., 1986, 119, 1331. 4 H. Keck, W. Kuchen, P. Thommes, J. K. Terlouw, T. Wong, Angew. Chem., Int. Ed. Engl., 1992, 31, 86.. 5 a) S. Ekici, D. Gudat, M. Nieger, L. Nyulaszi, E. Niecke, Angew. Chemie Int. Ed., 2002, 41, 3367. b) S. Ito, H. Miyake, M. Yoshifuji, T. Höltzl, T. Veszprémi, Chem. Eur. J., 2005, 11, 5960.

Uppsala University, SWEDEN O25 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Phosphine-Free Wittig Reaction Using Umpolung at Phosphorus

Anna C. Vetter, Kirill Nikitin and Declan G. Gilheany*

School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland [email protected]

We have developed a new general Umpolung1 approach for the synthesis of quaternary phosphonium salts (QPS), whereby the new group, e.g. R1, is introduced using an organometallic reagent (R1-M). In our methodology, nucleophilic attrack on the electron-poor P(V) moiety replaces the traditional quaternization approach (see A).2 The new substitution is very fast and high-yielding (up to 106-times faster than direct quaternization of phosphine).

QPS are a key class of organophosphorus compounds essential for many areas of chemistry, for example for Wittig-type olefinations. Our new Umpolung approach to QPS is based on phosphine oxide (a by-product of the Wittig reaction) and avoids the use of direct quaternization of phosphines which often suffer from limited nucleophilicity and availability. In a neat example of a shortcoming becoming an opportunity, the phosphine oxide problem is eliminated as Wittig reactions can now be run phosphine-free (B). Moreover, this route allows access to entirely new phosphonium salts and phosphine oxide structures.

Acknowledgement The authors gratefully acknowledge the Synthesis and Solid State Pharmaceutical Centre for financial support (12/RC/2275). References

1 B.-T. Gröbel, D. Seebach, Synthesis 1977, 357-402 2 A. C. Vetter, K. Nikitin, D. G. Gilheany, submitted manuscript.

Uppsala University, SWEDEN O26 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis of Conformationally Constrained Aminomethylene gem- Bisphosphonic Acids

Rubén Oswaldo Argüello-Velasco,a Pawel Kafarski,a Mario Ordoñezb aDepartment of Bioorganic Chemistry, Faculty of Chemistry, Wrocław University of Science and Technology. Wroclaw. Poland. bCentro de Investigaciones Quimicas-IICBA, Universidad Autonoma del Estado de Morelos. Cuernavaca, Morelos. Mexico. [email protected]

Cyclic aminomethylene gem-bisphosphonic acids are considered as promising anticancer, antiinflammatory, antiparasitic, antiviral and antibacterial agents1, as they produce inhibitory effect towards a variety of enzymes. Despite acknowledged biological importance of acyclic aminomethylene gem-bisphosphonic acids, much remains to be explored about the synthesis and biological activity of their cyclic counterparts. Preliminar studies consider derivates of pyrrole oxides as a new class of spin traps.2 Thus, we have decided to study the reactivity of different cyclic amides, basing on the results described by Chmielewska and co-workers2. The reaction was carried out using the corresponding amide with (EtO)3P prompted by POCl3 to give the corresponding bisphosphonate, which upon hydrolysis with 6M HCl should yield desired acids (Figure 1). However, this reaction appeared quite complex yielding many unexpected products.

Figure 1 Acknowledgement The authors gratefully acknowledge the COST action by a statutory activity subsidy from the Polish Ministry of Science and Education for the Faculty of Chemistry of Wrocław University of Science and Technology References 1 a) Neville-Webbe, H. L.; Gnant, M.; Coleman, R. E. Semin. Oncol. 2010, 37, S53-S65. b) Toussirot, E.; Wendling, D. Curr. Opin. Rheumatol. 2007, 19, 340-345. C) Singh, A. P.; Zhang, Y.; No, J. H.; Docampo, R.; Nussenzweig, V.; Oldfield, E. Antimicrob. Agents Chemother. 2010, 54, 2987-2993. d) Agapkina, J.; Yanvarev, D.; Anisenko, A.; Korolev, S.; Vepsäläinen, J.; Kochetkov, S.; Gottikh, M. Eur. J. Med. Chem. 2014, 73, 73-82. e) Forlani, G.; Petrollino, D.; Fusetti, M.; Romanini, L.; Nocek, B.; Joachimiak, A.; Berlicki, Ł.; Kafarski, P. Amino Acids 2012, 42, 2283-2291. 2 Olive, G.; Le Moigne, F.; Mercier, A.; Rockenbauer, A.; Tordo, P. J. Org. Chem. 1998, 63, 9095-9099. 3 Chmielewska, E.; Miszczyk, P.; Kozlowska, J. Prokopowicz, M. Mlynarz, P. Kafarski, P. J. Organomet. Chem. 2015, 785, 84-91.

Uppsala University, SWEDEN O27 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Using silylphosphanes as ligands - synthetic and theoretical investigations of diphosphastannylenes

Elisabeth Schwarz,a Stefan Müller, Ana Torvisco and Michaela Flock*

aInstitute of Inorganic Chemistry, Graz University of Technology. Graz. Austria. @ [email protected]

The number of publications that examine α,α′ - nitrogen stabilized cyclic carbenes (NHC, Arduengo carbenes) is quite large given that there is just one analogous α,α′- phosphorus stabilized compound of this type[1]. Both, NHCs and their heavier analogous diaminotetrylenes, have, due to their high reactivity, substantial possibilities in transition metal catalysis. Although there is just one cyclic diphosphatetrylene several acyclic ones are known in literature. Most of these diphosphatetrylenes are either stabilized by intermolecular bases or via dimerization. Monomeric diphosphatetrylenes usually feature very bulky substituents for stabilization [2,3]. Izod[4] recently characterized monomeric diphosphastannylenes and –germylenes with large substituents that have one planar phosphorus centre which might aid the stabilisation. Using calculations at the DFT level together with exact cone angle calculations[5] we explored the stabilization effects of various phosphorus substituents (H, Me, tBu, Ph, TMS,

Hyp=(Si(SiMe3)3)) on diphosphastannylenes. Our synthetic work led to the isolation if two supermesityl(trimethylsily)phosphanides and the characterisation of a novel monomeric diphosphastannylene, [HypP(SiMe3)]2Sn.

R R

P P

R Sn R

R = H, Me, tBu, TMS, Hyp, Ph R’ = Mes*, Hyp Acknowledgement The authors gratefully acknowledge the COST action CM1302 (SIPs). References 1 D. Martin, A. Baceiredo, H. Gornitzka, W.W. Schoeller, G. Bertrand, Angewandte Chemie International Edition 2005, 44, 1700–1703. 2 M. Driess, R. Janoschek, H. Pritzkow, S. Rell, U. Winkler, Angew. Chem. Int. Ed., 1995, 1614. 3 T. Řezníček, L. Dostál, A. Růžička, R. Jambor, Eur. J. Inorg. Chem., 2012, 2983. 4 K. Izod, P. Evans, P.G. Waddell, M.R. Probert, Inorganic Chemistry, 2016, 10510–10522. 5 J.A. Bilbrey, A.H. Kazez, J. Locklin, W.D. Allen, J. Comput. Chem. 2013, 34, 1189–1197.

Uppsala University, SWEDEN O28 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

POSTER PRESENTATIONS

Uppsala University, SWEDEN European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Preparation and utilization of chiral organophosphorus compounds

Péter Bagi,a,* Réka Herbay,a Bence Varga,a György Keglevicha

a Department of Organic Chemistry and Technology, Budapest University of Technology and Economics. Budapest. Hungary. [email protected]

Optically active organophosphorus compounds, especially the ones bearing P-stereogenic center(s) are of great importance in organic syntheses. An important application is the use of chiral P-ligands in transition metal catalysts [1]. Moreover, these compounds can also be organocatalysts in their own right [2]. However, there are a few methods available for the preparation of P-chiral compounds, which is still a limiting factor for their widespread application [3]. In our work, we aim the develepment of novel or complementary strategies for the preparation of optically active P-stereogenic compounds. Our methods are based on the formation of diastereomeric host-guest complexes or covalent diastereomers. Moreover, chiral auxilliary free purification strategies of the corresponding enantiomeric mixtures are also investigated. Besides the tertiary phosphine oxides, secondary phosphine oxides and H-phosphinates are also in the scope of our methods, as the latter two species are valuable P-chiral intermediates. The application of the optically active P-chiral species was also investigated as ligands in transition metal catalyzed reactions or as organocatalysts in enantioselective Wittig-olefination.

Acknowledgement This work was supported by the National Research, Development and Innovation Office - NKFIH (Grant No. OTKA PD 116096). Péter Bagi thanks the financial support of the ÚNKP-17-4-I-BME-102 New National Excellence Program of the Ministry of Human Capacities. References 1 A. Börner Ed., Phosphorus Ligands in Asymmetric Catalysis, Wiley-VCH, Weinheim, 2008. 2 M. Benaglia, S. Rossi, Org. Biomol. Chem. 2010, 8, 3824-3830. 3 M. Dutartre, J. Bayardon, S. Jugé, Chem. Soc. Rev. 2016, 45, 5771-5794.

Uppsala University, SWEDEN P1 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Sterically Constrained Tricyclic PC3 Phosphines Unusual Coordination Behavior and Reactivity

Alexander Branda, Anne Hentschela, Philipp Wegenera, Werner Uhla

aInstitut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Germany. [email protected]

The reaction of the trilithium compounds 1 and 2 with PCl3 leads to the selective formation of the sterically constrained tricyclic phosphines 3 and 4.1,2 The carbon backbone of compounds 3 and 4 consists exclusively of sp2-hybridized C atoms, which force a strained surrounding of the P atoms with large C-P-C angles of 128°.

Compounds 5 and 6 were formed in oxidative halogenation reactions of 3. Their molecular structures show differing geometries at the phosphorus atoms (square pyramidal versus trigonal bipyramidal).1 Treatment of 5 with one equivalent of MeLi lead to the monoalkylated species 7 which shows a square pyramidal coordination sphere with the methyl group at the apical position. When treating 3 with two equivalents of sulfur and selenium, selective insertion reactions into one of the endocyclic P-C bonds and oxidative addition to the phosphorus atoms were observed (8 and 9).1

References 1 A. Hentschel, A. Brand, P. Wegener, W. Uhl, Angew. Chem. Int. Ed. 2018, 57, 832-835. 2 W. Uhl, A. Hentschel, D. Kovert, J. Kösters, M. Layh, Eur. J. Inorg. Chem. 2015, 2486–2496. 3 A. Hentschel, Dissertation, Münster 2015.

Uppsala University, SWEDEN P2 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Homogeneous Systems for Selective Olefin Oligomerisation Synthetic Routes towards Bidentate, Mixed-functional (L2X^L) Ligands

Claire N. Brodie,a Andrei S. Batsanov,a Martin J. Hantonb and Philip W. Dyera,c,*

aDepartment of Chemistry, Durham University. Durham. United Kingdom. bSasol Technology (UK) Ltd. St Andrews. UK. cCentre for Sustainable Chemical Processes, Department of Chemistry, Durham Univeristy. Durham. UK. [email protected]

5 2 The complex [(η -C5Me5)Co(η -C2H4)(P(OMe)3] (1) {(L2X)-M-L} has been reported in the literature as a pro-initiator for dimerisation of 1-butene, 1-hexene and 1-octene to the corresponding linear α- olefins (LAOs) with selectivity higher than would be expected from thermodynamic considerations alone.1 Since the mechanism by which complex 1 controls selective LAO dimerisation is not fully established, to aid understanding, the synthesis of a series of analogues to 1 where steric and electronic influences are varied is targetted. Derivatives to the precursor of complex 1 with general formula (L2X)Co(CO)2, where (L2X) is Cp, Cp* and indenyl, were synthesised. The reported oligomerisation reactions involving complex 1 occur with very low activity (1-hexene to 1-dodecene TOF 3.7 h–1).1 It is hypothesised that this low activity is the result of poor catalyst stability. In order to improve catalyst lifetime and therefore activity, investigation of (L2X)-type ligands tethered with a pendant hemi-labile L-type donor was undertaken.

Attempted synthesis of (L2X)-CH2CH2-L ligands via the intermediate (L2X)-CH2CH2-Br exclusively results in the formation of spiro[-1,9’-fluorene]. However, a synthetic route via the intermediate Cl-CH2CH2-L allows for successful synthesis of a series of (L2X)-CH2CH2-L ligands; an example is shown in Figure 1.

Figure 1 Synthesis of (L2X)-CH2CH2-PR2 ligands, where R can be aryl or alkyl and (L2X) is fluorenyl or indenyl.

Acknowledgement The authors gratefully acknowledge financial support from Sasol Technology UK and Durham University. References 1 R. D. Broene, M. Brookhart, W. M. Lamanna and A. F. Volpe Jr., J. Am. Chem. Soc., 2005, 5, 17194-17195

Uppsala University, SWEDEN P3 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Investigations of phosphorous containing biradicaloid derivatives: Activation of organic and diynes.

Lukas Chojetzki,a Axel Schulz,a,b Alexander Villinger,a Ronald Wustracka

aInstitut für Chemie, Abteilung Anorganische Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany. bLeibnitz-Institut für Katalyse e.V. an der Universität Rostock, Abteilung Materialdesign, Albert-Einstein-Straße 29a, 18059 Rostock, Germany. [email protected], [email protected]

Biradicaloids and their derivatives have been well studied over the last decades. The first biradicaloid, containing only pnictogenes was isolated and published by our group in 2011.[1]

Figure 1. Ph = Phenyl, Ter = 2,6-dimesitylphenyl

Investigations concerning its reactivity, derivatives and follow up chemistry have been done extensively.[2] This work especially focuses on the usage of conjugated organic dienes and diynes (Figure 1). Although those olefines can either react in a [2+2] or [2+4] cylcloaddition, only [2+2] cycloaddition products could be observed.[3]

References [1] T. Beweries, R. Kuzora, U. Rosenthal, A. Schulz, A. Villinger, Angew. Chem. Int. Ed. 2011, 123, 9136–9140. [2] A. Hinz, R. Kuzora, U. Rosenthal, A. Schulz, A. Villinger, Chem. Eur. J. 2014, 20, 14659–14673. [3] unpublished results.

Uppsala University, SWEDEN P4 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Simple functionalization and substitution of inversely polarized phosphaalkenes

Mario Cicač-Hudi,a M. W. Kaaz,a S. Bechtold,a S. H. Schlindwein,a C. Feil,a M. Niegerb and Dietrich Gudata,*

aInstitute for Inorganic Chemistry, University of Stuttgart. Stuttgart. Germany. bDepartment of Chemistry, University of Helsinki. Helsinki. Finland. [email protected]

Inversely polarised phosphaalkenes (ippas), which may formally also be considered phosphorus(I) compounds, are of rising interest as substrates for further functionalization reactions. A topic that is currently receiving increasing attention is the derivatization of the PH-function in 1[1].

Herein we will report our latest studies of the iodination of ippas (reaction I) to give 2, which are exhibiting a surprisingly structural variability and stability. The bonding situation of these compounds, which can alternatively be considered as hydro iodides, carbene-stabilized secondary diiodophosphanes, as zwitterionic phosphoranides, as onio-stabilized P(H)-functionalized halogenephosphanes or as organo-main group element charge transfer complexes of the iodine, will be discussed based on structural data and DFT calculations. The synthetic procedure is also transferable to cyclic phosphamethine cyanines 3 which can be converted to diiodophosphorane salts 4 (reaction II). Finally, the metal free substitution of the PH function of 1 by bromo borolidine 5 will be shown. Acknowledgement The authors gratefully acknowledge the DFG and University of Stuttgart for financial support, as well as support by the state of Baden-Württemberg through bwHPC. References 1 a) A. M. Tondreau, Z. Benkö, J. R. Harmer, H. Grützmacher, Chem. Sci. 2014, 5, 1545-1554; M. Bispinghoff, A. M. Tondreau, H. Grützmacher, C. A. Faradji, P. G. Pringle, Dalton Trans. 2015, 45, 5999-6003; A. Beil, R. J. Gillard Jr., H. Grützmacher, Dalton Trans. 2016, 45, 2044-2052; C. Slootweg, T. Krachko, M. Bispinghoff, A. Tondreau, D. Stein, M. Baker, A. Ehlers, H. Grützmacher, Angew. Chem. Int. Ed. 2017, 56(27), 7948-7951 (for P-Ph derivatives); b) L. Liu, D. A. Ruiz, F. Dahcheh, G. Bertrand, Chem. Commun. 2015, 51, 12732-12735; c) O. Lemp, C. von Hänisch, Phosphorus, Sulfur, and Silicon 2016, 191(4), 659-661; O. Lemp, M. Balmer, K. Reiter, F. Weigend, C. von Hänisch, Chem. Commun. 2017, 53(54), 7620-7623 (for saturated NHC-PH); d) M. Peters, A. Doddi, T. Bannenberg, M. Freytag, P. G. Jones, M. Tamm, Inorg. Chem. 2017, 56(17), 10785-10793 (for TM complexes).

Uppsala University, SWEDEN P5 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Unsymmetrical alkenes from two aldehydes via phosphaalkene and phosphinate intermediates

Nicolas D Imperioa, Anna Arkhypchukb.

a, b Department of chemistry Ångström, Uppsala University, 75120 Uppsala, Sweden. [email protected]

The formation of unsymmetrical alkenes from the intermolecular reductive coupling of two different aldehydes is described. The one-pot procedure consists of a sequence of three different steps (scheme 1) : a first aldehyde is converted, via phospha-Peterson reaction [1], to a phosphaalkene intermediate which is then transformed, upon addition of MeOH and oxidation [2], into a phosphinate specie that reacts with a second aldehyde to achieve the desired alkene.

Scheme 1: General reaction scheme.

The described reaction is free of transition metals, proceed at ambient temperature and it allows to synthetize a variety of substituted unsymmetrical olefins in good to excellent overall yield [3]. The reaction scope is wide since it tolerates a plethora of different substituents on feedstock aldehydes to construct C=C double bond, as reported in figure 1.

Figure 1: Aldehydes used for C=C double bond construction

References [1] M. Yam, J. H. Chong, C. Tsang, B. O. Patrick, A. E. Lam, D.P. Gates et al., Inorg. Chem 2006, 45, 5225-5234. [2] T. A. Knaap, T. C. Klebach, R. Lourens, M. Vos, F. Bickelhaupt, J. Am. Chem. Soc. 1983, 105, 4026-4032. [3] N. D. D Imperio, A. Arkhypchuk, S. Ott, manuscript in preparation.

Uppsala University, SWEDEN P6 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Dendritic Biferrocenyl Phosphane Ligands for Redox-Switchable Catalysis

Volker J. Eilrich,a,b A.-M. Caminade c and Evamarie Hey-Hawkins a,*

aInstitut für Anorganische Chemie, Fakultät für Chemie und Mineralogie, Universität Leipzig. Leipzig. Germany. bInstitut für Chemie, Martin-Luther-Universität Halle-Wittenberg. Halle. Germany. cLaboratoire de Chimie de Coordination, CNRS. Toulouse. France. [email protected]

Based on our previous work, [1] ruthenium complexes with biferrocen-1,1 ‴-diyl phosphane ligands were synthesised, two of them as first and second generation dendrimers [2] (Fig. 1). Ligands and ruthenium complexes have been characterised electrochemically by cyclic voltammetry (Fig. 2) to investigate the suitability of the complexes for redox-switchable catalysis. Furthermore, three complexes have been tested in the catalytic redox isomerisation of 1-octen-3-ol;[3] no dendritic effect [4] was observed.

Fig. 1: Dendritic biferrocenyl phosphane ruthenium Fig. 2: Cyclic voltammograms of the biferrocenyl phos- complex (2 nd generation). phane ruthenium complexes.

Acknowledgement The authors gratefully acknowledge the COST Action CM1302 Smart Inorganic Polymers (SIPs) for financial support.

References 1 a) P. Neumann, H. Dib, A.-M. Caminade, E. Hey-Hawkins, Angew. Chem. 2015 , 127 , 316–319; Angew. Chem. Int. Ed. , 2015 , 54 , 311–314; b) P. Neumann, H. Dib, A. Sournia-Saquet, T. Grell, M. Handke, A.-M. Caminade, E. Hey-Hawkins, Chem. Eur. J. 2015 , 21 , 6590–6604. 2 N. Launay, A.-M. Caminade, R. Lahana, J.-P. Majoral, Angew. Chem. 1994 , 106 , 1682–1684; Angew. Chem. Int. Ed. , 1994 , 33 , 1589–1592. 3 V. Cadierno, S. E. García-Garrido, J. Gimeno, A. Varela-Alvarez, J. A. Sordo, J. Am. Chem. Soc. 2006 , 128 , 1360–1370. 4 A.-M. Caminade, A. Ouali, R. Laurent, C.-O. Turrin, J.-P. Majoral, Chem. Soc. Rev. 2015 , 44 , 3890–3899.

Uppsala University, SWEDEN P7 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

P-tert-Butyl substituted oxaphosphirane complexes and their epoxide- like reactivity

Jan Faßbender,a Arturo Espinosa Ferao,b,* and Rainer Streubela,*

a Institute of Inorganic Chemistry, University of Bonn, Gerhard-Domagk-Straße 1, D-53121 Bonn, Germany b Department of Organic Chemistry, University of Murcia, Campus de Espinardo, E-30100 Murcia, Spain [email protected]

Since oxaphosphirane complexes, which are already known since 1990,[1] became readily available via the reaction of Li/Cl phosphinidenoid complexes with carbonyl compounds in 2007, [2a] their re- activity has been intensely studied.[2b-d] Nevertheless, the research was somehow hampered by the employed bulky P-substituents which were tedious to synthesize and also decreased the reactivity of the formed complexes. This might be one reason why oxaphosphirane complexes have not yet been established as building blocks in polymer chemistry. To overcome these limitations, we decided to establish and exploit a smaller P-substituent such as tert-butyl in Li/Cl phosphinidenoid complex chemistry. First results on the formation of 1 and oxa- phosphirane complex 2 as well as novel ring opening reactions using HCl, H2O or NH3 to furnish 3 (E = Cl, OH, NH2) will be presented; theoretical investigations revealed the need of several explicit HE molecules providing a proton-transfer bridge for these stereoselective reactions.[3] Furthermore, results from follow-up studies on reactions of complexes 3 shall be presented.[3]

Acknowledgement The authors gratefully acknowledge the COST action CM1302 (SIPs), financial support by the DFG (STR 411/26-3 and 411/29-3) and the computational resources provided by the Servicio de Cálculo Científico (University of Murcia). References 1 S. Bauer, A. Marinetti, L. Ricard, F. Mathey, Angew. Chem. Int. Ed. Engl. 1990, 29, 1166. 2 a) A. Özbolat, G. von Frantzius, J. Marinas Pérez, M. Nieger, R. Streubel, Angew. Chem. Int. Ed. Engl. 2007, 46, 9327; b) H. Helten, J. Marinas Peréz, J. Daniels, R. Streubel, Organometallics 2009, 28, 1221; c) H. Helten, J. Marinas Peréz, J. Daniels, R. Streubel, Chem. Asian J. 2011, 6, 1539; d) C. Albrecht, L. Shi, J. M. Pérez, M. van Gastel, S. Schwieger, F. Neese, R. Streubel, Chem. Eur. J. 2012, 18, 9780. 3 J. Faßbender, N. Künemund, A. Espinosa Ferao, G. Schnakenburg, R. Streubel, submitted.

Uppsala University, SWEDEN P8 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

N-Heterocyclic Phosphenium-Nitrosyl-Complexes of Chromium Reactivity Studies and their Use in -Borane Dehydrocoupling

Christoph Feil,a Simon H. Schlindwein,a and Dietrich Gudata,*

aInstitut für Anorganische Chemie, Universität Stuttgart, Germany. @ [email protected]

In consideration of their ability to support ligand bonding modes which allow no clear destinction between a formal cationic (phosphenium) or anionic (phosphido) character of the ligand, N- heterocyclic phosphenium (NHP) like (1)OTf and (1sat)OTf (see figure 1) show an analogy to the nitrosyl ligand.1,2 We report here the synthesis of the complexes (2) and (2sat) which offer a possibility to compare both types of ligands in the same complex.

Figure 1: Reaction scheme for the preparation of (2) and (2sat). This discussion of the coordination properties of the NHP and NO units will be lead based on spectral and structural properties of (2) and (2sat) as well as on their reactivity towards nucleophiles and electrophiles. As an example for these studies, the stepwise addition of H2 to the P-Cr bond will be discussed (see figure 2). Furthermore, the application of both complexes (2) and (2sat) as catalysts for the dehydrocoupling of ammonia-borane will be illustrated.

sat Figure 2: Reaction scheme for the stepwise addition of H2 towards (2) and (2 ).

References 1 L. Rosenberg, Coord. Chem. Rev. 2012, 256, 606-626 2 B. Pan, Z. Xu, M. W. Bezpalko, B. M. Foxman, C. M. Thomas, Inorg. Chem., 2012, 51, 4170-4179

Uppsala University, SWEDEN P9 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis of Fluorophosphonium Triflate Salts and their Application as Catalyst for the synthesis of N-Sulfonyl formamidines

Chunxiang Guo, Sivathmeehan Yogendra, Felix Hennersdorf, David Harting, Jan J. Weigand

Chair of Inorganic Molecular Chemistry, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Germany. Chunxiang,[email protected]

Fluorophosphonium derivatives exhibit a highly Lewis acidic phosphorus atom[1] and some possess a remarkable potential in catalytic reactions.[1-3] The synthesis of these derivatives usually includes the fluorination of an appropriate phosphane with XeF2 and subsequent fluoride abstraction with e.g. [1-4] [5] example [Et3Si][B(C6F5)4] or Me3SiOTf.

In this contribution, we report a convenient and high yielding protocol for the synthesis of fluorophosphonium cations as triflate salts. Formal F+-transfer towards phosphanes is achieved with - N-fluorobenzenesulfonimide (NFSI) and subsequent methylation of the anion [(PhSO2)2N] to give the corresponding fluorophosphonium triflate salts and Me[N(SO2Ph)2] (Scheme 1).

Scheme 1: Synthesis of the fluorophosphonium triflate salts.

These fluorophosphonium triflate salts exhibit remarkable Lewis acidiy in stoichiometric reactions with nucleophiles such as Me2NCHO and act as excellent catalysts for transformation of foramides into N-sulfonyl formamidines (Scheme 2).

Scheme 2: Catalytic cycle of the [R3PF][OTf] promoted transformation of foramides into N-sulfonyl formamidines and the + molecular structure of the [(Me2NCHO)(C6F5)3PF] cation.

Acknowledgement The authors thank the ERC (SynPhos 307616) and China Scholarship Council (CSC No. 201506200056) for financial support. References 1 C. B. Caputo, L. J. Hounjet, R. Dobrovetsky, D. W Stephan, Science 2013, 341, 1374 – 1377. 2 M. H. Holthausen, M. Mehta, D. W. Stephan, Angew. Chem. Int. Ed. 2014, 53, 6538 – 6541. 3 M. Perez, Z. W. Qu, C. B. Caputo, V. Podgorny, L. J. Hounjet, A. Hansen, R. Dobrovetsky, S. Grimme, D. W. Stephan, Chem. Eur. J. 2015, 21, 6491 – 6500. 4 M. Perez, T. Mahdi, L. J. Hounjet, D. W Stephan, Chem. Commun. 2015, 51, 11301 – 11304. 5 K. Schwedtmann, R. Schoemaker, F. Hennersdorf, A. Bauza, A. Frontera, R. Weiss, J. J Weigand, Dalton Trans. 2016, 45, 11384 – 11396.

Uppsala University, SWEDEN P10 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Comparing Frustrated Lewis Pair Chemistry to Metal-Ligand Cooperativity

E. R. M. Habraken,a Andreas W. Ehlers,a J. Chris Slootwega aVan ‘t Hoff Institute for Molecular Sciences, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands @ [email protected]

The discovery of main-group systems, such as frustrated Lewis pairs (FLPs), possessing a lone pair of electrons and a vacant orbital have shown to be able to activate small molecules [1]. This too holds for metal-ligand cooperativity (MLC), where both the metal and ligand are involved in both activation processes [2]. A typical MLC system consists of a pincer-type tridentate PNP ligand with a Lewis basic site located in the ligand and a Lewis acidic metal centre (see Figure 1).

Figure 1. A geminal frustrated Lewis pair (left) and a metal-ligand cooperativity system (right)

Pivotal to FLP chemistry is the prevention of Lewis adduct formation, which is accomplished by using sterically encumbered Lewis acidic and basic sites. Sterically unencumbered FLPs are able to dimerize, which leads to mutual quenching. We recently discovered that when MLC systems also contain sterically unencumbered groups, they dimerize thereby reducing their activity in stoichiometric and catalytic processes.

The similarities and differences between various FLP and MLC systems using experimental and theoretical means will be delineated. By doing so, guiding principles can be formulated for cooperative Lewis acid/base chemistry and catalysis.

Acknowledgement The authors gratefully acknowledge the Council for Chemical Sciences of The Netherlands Organization for Scientific Research (NOW/CW). References

1 D.W. Stephan, G. Erker, Angew. Chem. Int. Ed., 2015, 54, 6400-6441 2 C. Gunanathan, Y. Ben-David, D. Milstein, Science, 2007, 317, 790-792

Uppsala University, SWEDEN P11 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis and reactivity of quasi-bismatranes

Dominikus Heift* and Jamie Barrett

Department of Chemistry, Durham University, Durham United Kingdom [email protected]

3- Tripodal ligands, such as triamidoamine [N-(RNCH2CH2)3] , have attracted considerable interest over a period of time. They bind to main group or transition metals and create a sterically protected, 3-fold-symmetric pocket around the metal atom, so-called atrane complexes.1 Only a very few atrane compounds holding the heavy pnictogen element bismuth, so-called bismatranes,2,3 have been reported and no investigations on the potential of such bismuth compounds for homogeneous catalysis have been undertaken so far. In course of our work on designing and applying innovative heavy main group element-based molecular structures as catalysts for homogeneous bond activation processes, we are particularly interested in molecular cage compounds exhibiting two catalytically active group 15 element active sites. Thus, in contrast to previously reported bismatrane compounds,2,3 here we describe synthetic access to so-called quasi-bismatranes, molecular cage systems with spatially separated bridgehead pnictogen sites.

SR

P P BiX3 RS SR Bi RS SR RS X X X X = Cl, Br, I Our particular attention in this work focuses on tris-γ-substituted thioether phosphines and their coordination to bismuth salts (halides and triflate), allowing us to access a set of benzylene-linked phosphine – bismuth cage systems. Comparable to proazaphosphatranes,4 certain derivatives exhibit an extraordinary basicity on the phosphorus site. The poster focuses on the fundamental chemical reactivity of innovative quasi- bismatrane cage systems and highlights their potential as catalysts for various bond activation processes.

References 1 J. G. Verkade, Coord. Chem. Rev., 1994, 137, 233-295. 2 P. L. Shutov, S. S. Karlov, K. Harms, D. A. Tyurin, A. V. Churakov, J. Lorberth and G. S. Zaitseva, Inorg. Chem., 2002, 41, 6147-6152. 3 L. E. Turner, M. G. Davidson, M. D. Jones, H. Ott, V. S. Schulz and P. J. Wilson, Inorg. Chem., 2006, 45, 6123-6125. 4 M. A. H. Laramay and J. G. Verkade, J. Am. Chem. Soc., 1990, 112, 9421-9422.

Uppsala University, SWEDEN P12 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

“P-ligand-free” palladium acetate-catalyzed P–C coupling reactions under microwave conditions

Réka Henyecz*, Zoltán Mucsi, Nóra Zsuzsa Kiss and György Keglevich

Department of Organic Chemistry and Technology, Budapest University of Technology and Economics. Budapest. Hungary. [email protected]

The Hirao reaction is a P–C coupling reaction that takes place between aryl- or vinyl-halides and dialkyl phosphites, H-phosphinates or secondary phosphine oxides. The first Hirao reaction was reported applying tetrakis(triphenylphosphine) palladium [Pd(PPh3)4] [1], then other methods were developed to replace the sensitive and expensive catalyst by Pd(II) salts and added mono- or bidentate P-ligands [2]. Our research group has found that the Hirao reaction may be performed in the presence of palladium acetate or nickel chloride under microwave (MW) and solvent-free conditions without adding a usual P-ligand [3]. Our aim was to study the theoretical background of the MW-assisted palladium-catalyzed “P-ligand-free” P–C coupling reaction and to find out the role of the >P(O)H reactants [4].

The experimental results have shown that in the presence of 10% Pd(OAc)2, the application of 1.3 equivalents of the >P(O)H compounds is the optimum. The excess of the >P(O)H reagent, existing under a tautomeric equilibrium, may serve as the P-ligand and may also promote the reduction of Pd(II) before entering the catalytic cycle. All these suppositions were confirmed by quantum chemical calculations.

Acknowledgement The authors gratefully acknowledge the Gedeon Richter's Talentum Foundation. References 1 a) T. Hirao, T. Masunaga, Y. Ohshiro, T. Agawa, Tetrahedron Lett. 1980, 21, 3595-3598. b) T. Hirao, T. Masunaga, N. Yamada, Y. Ohshiro, T. Agawa, Bull. Chem. Soc. Jpn. 1982, 55, 909-913. c) T. Hirao, T. Masunaga, Y. Ohshiro, T. Agawa, Synthesis 1981, 56-57. 2 a) E. Jablonkai, G. Keglevich, Curr. Org. Synth. 2014, 11, 429-453. b) E. Jablonkai, G. Keglevich, Org. Prep. Proceed. Int. 2014, 46, 281-316. 3 a) E. Jablonkai, G. Keglevich, Tetrahedron Lett. 2013, 54, 4185-4188. b) E. Jablonkai, L. B. Balázs, L., G. Keglevich, RSC Adv. 2014, 4, 22808-22816. 4 G. Keglevich, R. Henyecz, Z. Mucsi, N. Z. Kiss, Adv. Synh. Catal. 2017, 359, 4322-4331.

Uppsala University, SWEDEN P13 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Investigation of the isomerization of phospholene oxides

Réka Herbay, Nikolett Péczka, Péter Bagi, Elemér Fogassy, György Keglevich

Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, Budapest, Hungary [email protected]

The five-membered P-heterocycles form an important class, as they are valuable starting materials for ligands or other heterocyclic derivatives.1 Although the preparation and the reactions of this class of compounds are well documented, the isomerization of the 3-phospholene oxides (1) to the corresponding 2-phospholene derivatives (2) has not been studied in detail. The importance of the 2- phospholene oxides (2) lies in the fact that they may be starting materials for phospha-sugars having antitumor activity.2 Previously it was observed, that 2-phospholene derivatives (2) may have formed as a side products in various reactions of 3-phospholene derivatives (1).3 Therefore, the first aim of this study was the investigation of the isomerization of 3-phospholene oxides (1) under thermal conditions. The application of various acids or bases was also tested. The isomerization of 3-phospholene oxides was elaborated via the formation of halophosphonium salts.4 In this reaction, the 3-phospholene oxide (1) was reacted with oxalyl chloride to form 3- phospholenium salt (3), which isomerized to thermodynamically more stable 2-phospholenium salt (4). The chlorophosphonium salt (4) was then hydrolized to give the corresponding 2-phospholene oxide (2). In this study, a series of new 2-phospholene oxides (2) and instable chloro-2-phospholenium chlorides (4) were prepared and characterized.

Acknowledgement Authors are thankful to Hungarian Research Fund for financial support (Grant No. PD116096). References 1 Kollár, L.; Keglevich, G.; Chem. Rev., 2010, 110, 4257. 2 a) Fujie, M.; Nakamura, S.; Asai, K.; Niimi, T.; Yamashita, J.; Kiyofuji, K.; Shibata, K.; Suzuki, M.; Aoshima, R.; Urano, T.; Yamashita, M.; Ilhan, Ö. Heterocycl. Commun. 2009, 15, 273. 3 a) Kiss, N. Z.; Ludányi, K.; Drahos, L.; Keglevich, G. Synt. Comm. 2009, 39, 2392., b) Bálint, E.; Jablonkai, E.; Bálint, M.; Keglevich, G. Heteroatom Chem. 2010, 21, 211. c) Keglevich, G.; Rádai, Z.; Harsági, N.; Szigetvári, Á.; Kiss, N. Z. Heteroatom Chem. 2017, 28, e21394. 4 Herbay R.; Bagi, P.; Mucsi, Z.; Mátravölgyi, B.; Drahos, L.; Fogassy, E.; Keglevich, G. Tetrahedron Lett. 2017, 58, 458.

Uppsala University, SWEDEN P14 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Limitations of Steric Bulk Towards Phospha-Germynes and Phospha-Stannynes

Alexander Hinz*a and Jose M. Goicoechea*a

a Department of Chemistry, University of Oxford, 12 Mansfield Road, OX1 3TA, Oxford, UK [email protected]

The use of sterically bulky ligands has been critical in the stabilisation of unusual structural motifs which violate the double bond rule. Since Lappert’s discovery of the first distannene, many landmark examples such as West’s disilene, Yoshifuji’s diphosphene, Tokitoh’s dipnictenes, Sekiguchi’s disilyne and Power’s alkyne analogues have been reported.[1] More recently, Jones and co-workers have exploited bulky [bis(benzhydryl)aryl](silyl)amides as substituents, allowing for the stabilisation of monomeric germanium hydrides and unsupported covalent bonds between main group elements and transition metals such as manganese and magnesium.[2]

We envisaged the synthesis of nitrile analogs (R–GeP, R–SnP) stabilised by only one of the Jones- type amido substituents via photolysis of the corresponding phosphaketenes R–GePCO and R–SnPCO (1). Amongst other products, the formation of germylenyl- and stannylenyl-substituted diphosphenes (2) was observed. Further enhancement of the steric bulk allowed the prevention of dimersation of R–GeP and R–SnP, but the heavy nitrile analogues could not yet be observed, as the substituent was subject to Si–C and C–H bond activations.

Acknowledgement The authors gratefully acknowledge the EPSRC for funding (grant EP/M027732/1). References [1] a) P. J. Davidson, D. H. Harris, M. F. Lappert, J. Chem. Soc., Dalton Trans 1976, 21, 2268– 2274; b) R. West, M. J. Fink, J. Michl, Science 1981, 214, 1343–1344; c) M. Yoshifuji, I. Shima, N. Inamoto, K. Hirotsu, T. Higuchi, J. Am. Chem. Soc. 1981, 103, 4587–4589; d) N. Tokitoh, Y. Arai, R. Okazaki, S. Nagase, Science 1997, 277, 78–80; e) A. Sekiguchi, R. Kinjo, M. Ichinohe, Science 2004, 305, 1755–1757; f) M. Stender, A. D. Phillips, R. J. Wright, P. P. Power, Angew. Chem. Int. Ed. 2002, 41, 1785–1787. [2] T. J. Hadlington, B. Schwarze, E. I. Izgorodina, C. Jones, Chem. Commun. 2015, 51, 6854– 6857; J. Hicks, C. E. Hoyer, B. Moubaraki, G. L. Manni, E. Carter, D. M. Murphy, K. S. Murray, L. Gagliardi, C. Jones, J. Am. Chem. Soc. 2014, 136, 5283–5286.

Uppsala University, SWEDEN P15 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Dipnictenes Bearing Anionic N-Heterocyclic Carbenes

Luong Phong Ho,a Ahmet Altun,b Giovanni Bistoni,b Matthias Freytaga and Matthias Tamma

aInstitut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Germany. bDep. of Molecular Theory and Spectroscopy, MPI for Chemical Energy Conversion, Mülheim and der Ruhr, Germany. [email protected]

With the rise of N-heterocyclic carbenes as versatile and important ligands in main group chemistry,1 their use to stabilize doubly bonded systems have become more and more common. As a result, earlier in this decade, the synthesis of bis(NHC) stabilized dipnictenes such as 1 were attained.2 Those novel complexes are dicationic in nature since the NHC itself is a neutral ligand. Overall neutrally charged and symmetrically substituted bis(NHC) dipnictenes were obtained within our workgroup very recently. As a first step, a salt metathesis reaction between our anionic carbene transfer reagent 23 and the corresponding pnictogen trihalides yielded the dihalopnictanes of type 3, which can serve as precursors towards the desired dipnictenes 4. The latter ones were accessible via a reductive coupling using a suitable reducing agent.

2 X–

N (C6F5)3B N (C6F5)3B N (C6F5)3B N E N EX3 [Red] E N Li(Tol) E N E X N E N N X N N B(C F ) E = P, As, Sb 6 5 3 X = Cl, Br

1: E = P, As 2 3 4 Scheme 1. Synthesis of neutral symmetrically substituted anionic NHC dipnictenes. In order to close the gab between the bis(NHC) and the bis(anionic NHC) stabilized dipnictenes, we were also interested in heteroleptic substituted dipnictenes. Therefore, we developed a modular approach with the carbene phosphinidene adduct 54 and the dihalopnictanes 3 to generate the diatomic main group element species 6. Subsequent chloride abstraction gives the unsymmetrically substituted monocationic complexes 7.

X–

(C F ) B (C F ) B (C6F5)3B N N TMS 6 5 3 N 6 5 3 N E E E + P N N Cl N Cl P – N P N Cl N – Cl E = P, As N N

3 5 6 7 Scheme 2. Synthesis of heteroleptic substituted dipnictenes.

References 1 Y. Wang, G. H. Robinson, Dalton Trans. 2012, 41, 337–345. 2 a) O. Back, B. Donnadieu, P. Parameswaran, G. Frenking, G. Bertrand, Nat. Chem. 2010, 2, 369–373. b) M. Y. Abraham, Y. Wang, Y. Xie, R. J. Gilliard, P. Wei, B. J. Vaccaro, M. K. Johnson, H. F. Schaefer, P. v. R. Schleyer, G. H. Robinson, J. Am. Chem. Soc. 2013, 135, 2486–2488. 3 S. Kronig, E. Theuergarten, C. G. Daniliuc, P. G. Jones, M. Tamm, Angew. Chem. Int. Ed. 2012, 51, 3240–3244. 4 a) A. Doddi, D. Bockfeld, T. Bannenberg, P. G. Jones, M. Tamm, Angew. Chem. Int. Ed. 2014, 126, 13786– 13790. b) A. Doddi, D. Bockfeld, M. K. Zaretzke, C. Kleeberg, T. Bannenberg, M. Tamm, Dalton Trans. 2017, 46, 15859–15864.

Uppsala University, SWEDEN P16 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Electronic Characteristics of Phosphorus Rich [3]Ferrocenophanes

Stefan Isenberg,a Denis Kargin,a Zsolt Kelemena and Rudolf Pietschniga,*

aInstitute of Chemistry, University of Kassel, Germany. [email protected]

[n]Ferrocenophanes are still particularly known for their ability to undergo thermal ring opening polymerisation (ROP) originating from the ring strain especially in [1]ferrocenophanes.[1] In recent years we demonstrated that phospha [n]ferrocenophanes with n = 2 and 3, in which the tendency to thermal ROP is significantly reduced, exhibit interesting stereospecific properties as well. We found that the expected number of isomers, due to the stereogenic phosphorus centers, can be diminished by embedding the phosphorus chain into a cyclic ferrocenophane backbone.[2-4] The electronic properties of triphospha [3]ferrocenophanes considerably differ whether the phosphorus lone pairs in the bridge interact in a cis like structure or alternate trans like in the chain.[4] These interesting features encouraged us to further investigate the electronic characteristics of such moieties, their derivatives incorporating different main group elements and their corresponding polyphosphorus dimers. We present the synthesis as well as electro chemical and EPR investigations of different phospha [3]ferrocenophanes towards intramolecular electron transfer[5] and radical formation.

Acknowledgements The authors gratefully acknowledge the COST action CM1302 (SIPs), the DFG (PI 353/8-1 & 9-1) as well as the SFB 1319 (ELCH) for financial support. References 1 i.e. I. Manners et al., Angew. Chem. Int. Ed. 2007, 46, 5060-5081; Organometallics 2013, 32, 5654-5667; Chem. Soc. Rev. 2016, 45, 5358-5407. 2 C. Moser, F. Belaj, R. Pietschnig, Chem. Eur. J. 2009, 15, 12589-12591. 3 D. Kargin, Z. Kelemen, K. Krekić, M. Maurer, C. Bruhn, L. Nyulászi, R. Pietschnig, Dalton Trans. 2016, 45, 2180-2189. 4 S. Borucki, Z. Kelemen, M. Maurer, C. Bruhn, L. Nyulászi, R. Pietschnig, Chem. Eur. J. 2017, 23, 10438- 10450. 5 A. Lik, D. Kargin, S. Isenberg, Z. Kelemen, R. Pietschnig, H. Helten, Chem. Commun. 2018, DOI:10.1039/c7cc09759j.

Uppsala University, SWEDEN P17 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Phosphaquinomethane Complexes: Studies on Formation and Properties

Philip Junker, Rainer Streubel*

University of Bonn, Institut für Anorganische Chemie, Gerhard-Domagk Straße 1, 53121 Bonn, Germany. [email protected]

Novel π-electron conjugated systems represent a great interest in the research and development of organic electronics, a quickly developing field of modern materials science.1 Among them the systems with reversible redox properties are particularly interesting. While initial insights into the redox chemistry of phosphaquinomethanes have been obtained previously,2 no information about the electronic properties of potentially more stable transition metal(0) complexes such as 2 is known thus far.

Herein, we present a systematic study on reactions of complexes 1 with [Ph3C]BF4 undergoing a stepwise reaction of a 1 e--oxidation reaction followed by a heterocoupling of the radical pair for- ming an intermediate complex.3 Depending on the added base and the P-substituent, the intermediate can undergo two different reaction pathways, a H-shift to form 3 or a HCl elimination to form 2. - Such complexes 2 are deeply coloured and capable of a reversible 1 e -reduction (-1.15 V, R = CPh3, + 4 vs Fc/Fc ) revealing a remarkable stabilizing effect of the M(CO)5 group.

Acknowledgement The authors gratefully acknowledge the COST action CM1302 (SIPs) and the Deutsche Forschungsgemeinschaft (SFB 813). References 1 a) H. Klauk (ed.), Organic Electronics II, Wiley-VCH, Weinheim, 2012; b) T. Akasaka, A. Osuka, S. Fukuzumi, H. Kandori, Y. Aso (eds.), Chemical Science of -Electron Systems, Springer Japan, 2015; c) T. Sasamori, N. Tokitoh, R. Streubel, -Electron Redox Systems of Heavier Group 15 Elements, in Organic Redox Systems, Synthesis, Properties and Applications (ed. T. Nishinaga), Wiley, Hoboken, New Jersey, 2016, 563-578. (ISBN 978-1-118-85874-5) 2 F. Murakami, S. Sasaki, M. Yoshifuji, J. Am. Chem. Soc., 2005, 127, 8926. 3 A. Özbolat-Schön, M. Bode, G. Schnakenburg, A. Anoop, M. v. Gastel, F. Neese, R. Streubel, Angew. Chem. Int. Ed. 2010, 49, 6894-6898. 4 P. Junker, J. M. Villalba Franco, G. Schnakenburg, V. Nesterov, R. T. Boere, Z.-W. Qu, R. Streubel, manuscript in preparation.

Uppsala University, SWEDEN P18 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis and Reactivity of a Boryl-Chloro-Phosphine

M. Kaaz,a C. Feil a, S. H. Schlindwein a, D. Gudat a

aInstitute of Inorganic Chemistry, University of Stuttgart. Stuttgart. Germany. [email protected]

P-hydrogen substituted N-heterocyclic-borylphosphines[1] are versatile precursors for further tranformations as they can be easily deprotonated with strong bases like BuLi. The formed phosphides allow alkylation/arylation with carbon based nucleophiles as well as introduction of a SiMe3 group by reaction with TMSCl. Oxidative cleavage of the PSi bond with C2Cl6 gives access to a boryl-chloro-phosphine.

While this boryl-chloro-phosphine is thermally relatively stable, it decomposes upon irradiation with UV-light. The decomposition products could be identified as a choro-borolene and cyclophosphanes, respectively. This fragmentation pattern suggests a phosphinidenoid-like reactivity.

This conjecture is corroborated by the observation that irradiation of the boryl-chloro-phosphine in dimethylbutadiene as a solvent results in a reaction under formal phosphinidene transfer to the to yield a phospholene.

References 1 M. Kaaz, J. Bender, D. Förster, W. Frey, M. Nieger, D. Gudat, Dalton Trans. 2014, 43, 680-689.

Uppsala University, SWEDEN P19 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Phospha-Carborane Containing Polymers for Preparation of Well- Defined Architecture

Gizem Kahraman,a Markus Gallei,b Evamarie Hey-Hawkinsc* and Tarik Erena,*

aDepartment of Chemistry, Yildiz Technical University. Istanbul. Turkey. b Department of Macromolecular Chemistry, Darmstadt Technical University. Darmstadt. Germany. c Department of Inorganic chemistry, University of Leipzig. Leipzig. Germany. [email protected]

The research presented in this project focuses on the development of novel functional hybrid organic-inorganic architectures containing chemically-tethered icosohedral carboranes. The motivation behind this work was to understand and overcome the challenges associated with the incorporation of inorganic boron clusters into a variety of well-defined polymeric architectures. This task was critical for the advancement of scientific understanding, as well as the improvement and implementation of novel hybrid materials towards technological applications.

Scheme 1. Polymers synthesized in this study

Acknowledgement The authors gratefully acknowledge the TUBITAK 114Z666 and COST action CM1302 (SIPs). References 1 Y.C. Simon, Macromolecules 2007, 40, 5628-5630.

Uppsala University, SWEDEN P20 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

First terminal phosphido complexes of iron supported by β-diketiminato ligand Catalytic activity in the dehydrocoupling of phosphines

Kinga Kaniewska,a Alina Dragulescu-Andrasi,b Łukasz Ponikiewski,a Jerzy Pikies,a Sebastian A. Stoianc and Rafał Grubbaa

aDepartment of Inorganic Chemistry, Gdańsk University of Technology. Gdańsk, PL 80-233. Poland. bDepartment of Chemistry and Biochemistry, Florida State University. Tallahassee, FL 32306. USA. cDepartment of Chemistry, University of Idaho. Moscow, ID 83844. USA. [email protected]

Nowadays, the synthesis of functionalized phosphorous compounds is one of the most important research field which leads to obtaining a novel group of synthetic reagents and biologically active molecules for the chemical industry. Excellent examples of such compounds are diphosphanes and their derivatives, for which, among many methods of synthesis, the ideal ways to formation of P-P and P-C bonds, due to high selectivity and efficiency, are dehydrocoupling1 and hydrophosphination2 reactions catalyzed by metal complexes. Recently, we have reported the synthesis of the first phosphido complexes of iron stabilized by β-diketiminato ligand and their catalytic activity in dehydrocoupling of phosphines. All obtained phosphido complexes are active catalysts in formation of diphosphane Ph2P-PPh2 from secondary phosphine Ph2PH. It is worth to emphasize that in these reactions, from not complicated substrate in the presence of small amount of non-toxic and not expensive catalyst, we can obtain diphosphane with high yield where the only by-product is hydrogen.

Acknowledgement K.K., Ł.P. and R.G. gratefully acknowledge the National Science Centre NCN, Poland (Grant no. 2016/21/B/ST5/03088) for financial support. References 1 A.K. King, A. Buchard, M.F. Mahon, R.L. Webster, Chem. Eur. J. 2015, 21, 15960-15963 2 M. Espinal-Viguri, A.K. King, J.P. Lowe, M.F. Mahon, R.L. Webster, ACS Catal. 2016, 6, 7892-7897

Uppsala University, SWEDEN P21 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Phosphinito complexes as precursors for anionic 1,3-ambiphilic systems

Robert Kunzmann, Rainer Streubel*

Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn. Germany. [email protected]

During the past decade, the chemistry of Li/X phosphinidenoid M(CO)5 complexes was well estab- lished1, but only few investigations were carried out on the tolerance towards additional functional 2 groups attached to the substituents on the phosphorus atom (R and OR and/or NR2). The latter ones could be the starting point for a new class of 1,3-ambiphilic systems. By tuning the substitution pattern, these may also serve as precursors in the synthesis of novel three membered-heterocyclic structures having a phosphorus and an oxygen atom as well as another main group element center in the ring system. Herein, we present a multistep synthetic protocol starting from lithium phosphinito complex3 I to novel 1,3-ambiphilic K/OEMe3 and K/OEMe2Cl phosphinidenoid complexes III (E = Si, Ge and Sn) as well as first reactivity studies (Scheme).4 Additionally, derivatization reactions of centers E in phosphane complexes II will be shown.

Acknowledgement The authors gratefully acknowledge the COST action CM1302 (SIPs) and the Deutsche Forschungsgemeinschaft (STR 411/26-3) for financial support. References 1 a) A. Özbolat, G. von Frantzius, J. M. Perez, M. Nieger, R. Streubel, Angew. Chem. Int. Ed. 2007, 46, 9327; b) A. Özbolat, G. von Frantius, W. Hoffbauer and R. Streubel, Dalton Trans 2008, 2674-2676; c) L. Duan, G. Schnakenburg and R. Streubel, Organometallics 2011, 30, 3246-3249; d) R. Streubel, A. W. Kyri, L. Duan and G. Schnakenburg, Dalton Trans. 2014, 43, 2088-2097. 2 a) A. W. Kyri, R. Kunzmann, G. Schnakenburg, Z.-W. Qu, S. Grimme, R. Streubel, Chem. Comm. 2016, 52, 13361; b) R. Streubel, A. Schmer, A. W. Kyri, G. Schnakenburg, Organometallics 2017, 36, 1488; c) P. K. Majhi, A. W. Kyri, A. Schmer, G. Schnakenburg and R. Streubel, Chem. Eur. J. 2016, 22, 15413-15419. 3 A. W. Kyri, G. Schnakenburg, R. Streubel, Chem. Comm. 2016, 52, 8593. 4 R. Kunzmann, A. Espinosa-Ferao, G. Schnakenburg, R. Streubel, manuscript in preparation.

Uppsala University, SWEDEN P22 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Novel P,B Lewis Pairs involving Phosphinines

Julia Leitl,a Evi R. M. Habraken,b J. Chris Slootwegb and Robert Wolf* a aDepartment of Inorganic Chemistry, University of Regensburg, 93040 Regensburg, Germany. b Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, 1090 GD Amsterdam, Netherlands. E-mail: [email protected]; [email protected]

The discovery of reversible H2 activation by p-(Mes2P)C6F4[B(C6F5)2] in 2006 initiated the rapid development of frustrated Lewis pair (FLP) chemistry.[1] FLPs based on phosphorus-based donors and boron-based Lewis acceptors were at the forefront of this development; both inter- and intramolecular P,B Lewis pairs were reported.[2] Beside FLP chemistry, phosphinoboranes are also of interest as ligands in coordination compounds.[3] Here, we present the synthesis of P,B Lewis pairs 1‒4 based on phosphinines as a reactive component. These new compounds were obtained by salt metathesis of [K([18]crown-6)(thf)2][Cp*Fe- [4,5] (PC5Ph3H2)] (5) and Li(RPC5Ph3H2) (6: R = Me, n-Bu). The formation of complex 2 involves an adventitious ring-opening of THF solvent molecules. Investigations on the synthesis of related P,B species and the reactivity of 1‒4 towards small molecules are currently under investigation.

References 1 G. C. Welch; R. R. S. Juan; J. D. Masuda; D. W. Stephan, Science 2006, 314, 1124−1126. 2 D. W. Stephan, J. Am. Chem. Soc. 2015, 137, 10018−10032. D. W. Stephan, G. Erker, Angew. Chem. Int. Ed. 2010, 49, 46−76. D. W. Stephan, G. Erker, Angew. Chem. Int. Ed. 2015, 54, 6400−6441. D. W. Stephan, G. Erker, Chem. Sci. 2014, 5, 2625–2641. 3 a) R. T. Paine, H. Noeth, Chem. Rev. 1995, 95, 343–379. b) J. A. Bailey, M. Ploeger, P.G. Pringle, Inorg. Chem. 2014, 53, 7763−7769. c) J. A. Bailey, M. F. Haddow, P. G. Pringle, Chem. Commun. 2014, 50, 1432−1434. d) A. M. Spokoyny, C. D. Lewis, G. Teverovskiy, S. L. Buchwald, Organometallics 2012, 31, 8478−8481. 4 B. R. Rad, U. Chakraborty, B. Mühldorf, J. A. W. Sklorz, M. Bodensteiner, C. Müller, R. Wolf, Organometallics 2015, 34, 622–635. 5 C. Hoidn, R. Wolf, Dalton Transactions 2016, 21, 8875–8884.

Uppsala University, SWEDEN P23 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Reactivity of Lewis base-free, trigonal planar oxophosphonium ions

Pawel Löwe, Marius Wünsche, Tim Witteler, Fabian Dielmann*

Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster,48149 Münster. Germany. [email protected]

Strong main group Lewis acids are of current interest, especially for the use in bond activation and catalysis. Recently phosphonium ions have been used as catalysts in the hydrodefluoration of fluoroalkanes.1 Another interesting class of strong Lewis acids are trigonal planar phosphorous cations such as oxophosphonium ions. These cations have not been prepared in free state so far and only Lewis base adducts have been reported.2

In this contribution we report on the synthesis and properties of free trigonal planar oxophosphonium ions. These species are stabilized by bulky, electron donating imidazolin-2-imin groups at the phosphorous atom. We show that the Lewis acidity of the trigonal planar phosphorus centre can be varied by the substituents attached to phosphorous. The electrophilicity of the oxophosphonium cations was experimentally determined by the Gutmann-Beckett method and by DFT calculations on the fluoride affinity (FIA). Preliminary studies on the reactivity of the novel species are presented.

References 1 C. B. Caputo, L. J. Hounjet, R. Dobrovetsky, D. W. Stephan, Science 2013, 341, 1374. 2 a) A. D. Hendsbee, N. A. Giffin, Y. Zhang, C. C. Pye, J. D. Masuda, Angew. Chem. Int. Ed. 2012, 51, 10836. b) G. Ilić, R. Gaguly, M. Petković, D. Vidović, Chem. Eur. J. 2015, 21, 18594. c) J. J. Weigand, N. Burford, D. Mahnke, A. Decken, Inorg. Chem. 2007, 46, 7689. d) J. Cui, Y. Li, R. Ganguly, R. Kinjo, Inorganica Chimica Acta 2017, 460, 2.

Uppsala University, SWEDEN P24 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Addition of the P-H bond to the Morita-Baylis-Hillman acetates as a route to non-covalent activity-based probes of metalloaminopeptidases

Marta Maślanka and Artur Mucha

Department of Bioorganic Chemistry, Faculty of Chemistry, Wroclaw University of Science and Technology [email protected]

Activity-based probes are invaluable tools for imaging the enzyme activity. Accordingly, they are of a great importance in the drug discovery and development.1 The most frequently the ability of biomarkers to monitor the enzyme activity and distribution is related to the covalent bonding between a nucleophile enzyme residue and the electrophilic substrate at the active site. The idea of non-covalent imaging is ambiguous and much less recognized. Typically, a reporter tag is conjugated with the inhibitor portion by an extended linker. In the current study we intend to perform transformation of the residue of a potent zinc-complexing ligand into the fluorescent fragment. The research will include the synthesis of the P1’ coumarin- based phosphinic dehydrodipeptides (Figure 1) that are modifications of a canonical inhibitor of alanyl (M1) and leucine metalloaminopeptidases (M17).2 The outcome of the study should allow to answer the question whether the inhibitory and fluorescent properties of such low-molecular weight molecules are maintained upon binding to the aminopeptidase active site.

Figure 1. Desisigned fluorescet phosphinodipeptide analog inhibitors of metalloproteases.

References 1 L. E. Sanman, M. Bogyo, Annual Review of Biochemistry, 2014, 83, 249–273. 2 A. Mucha, P. Kafarski, Ł. Berlicki, Journal of Medicinal Chemistry, 2011, 54, 5955–5980.

Uppsala University, SWEDEN P25 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Phosphorus(III) superbases: New prospects in small molecule activation

Paul Mehlmann,a Jennifer Börger,a Fabian Dielmann

Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Germany. [email protected]

As part of our program to enhance the donor strength of phosphines we reported a new approach to highly electron-rich phosphines based on the use of imidazolin-2-ylidenamino groups directly attached to the phosphorus atom.1 These phosphines are not only excellent electron donor ligands, but also display a new class of phosphorus(III) superbases.

+ Figure 1. TEP values and pKBH values of P(NIiPr)3 and selected phosphines and phosphazene superbases for comparison.

+ The determination of the phosphines basicity reveals pKBH (THF) values of up to 31.0 (Figure 1). 2 Thus, P(NIiPr)3 is the strongest reported nonionic phosphorus(III) superbase. The unique electronic properties of these phosphines provide new prospects in small molecule activation, which will be discussed in the present contribution.

Acknowledgement The authors gratefully acknowledge financial support from the DFG (SFB 858). References 1 M. Wünsche, F. Dielmann et al., Angew. Chem. Int. Ed. 2015, 54, 11857-11860. 2 P. Mehlmann, F. Dielmann et al., Chem. Eur. J., 2017, 23, 5929-5933.

Uppsala University, SWEDEN P26 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis of Diazaphosphinines by Inverse-Electron-Demand Diels- Alder Reactions of Na[OCP] with s-Tetrazines

Yanbo Mei, Jaap E. Borger, Hansjörg Grützmacher*

Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland. [email protected]

Phosphinines have wide application in coordination chemistry and catalysis.[1] On the other hand, azaphosphinines have barely been scrutinized, but could be interesting as multidentate ligands or exhibit attractive photophysical properties.[2] Only a few examples of diazaphosphines are known, while most other regio-isomers have yet to be prepared (Figure 1).[3]

The use of electron rich acetylenes for inverse-electron-demand Diels-Alder reactions to produce aromatic heterocycles is well known.[4] Because phosphorus shares a diagonal relationship with carbon in the periodic table, we envisioned that Na[O‒C≡P] could react with electron poor s-tetrazines to enable the formation of unique diazaphosphinines by extrusion of N2 (Figure 1).

In this work, we present a highly efficient synthesis of diazaphosphinines as stable 5-olate salts (A, Scheme 1, yield > 85%) from the reaction of the phosphaethynolate anion with s-tetrazines. These salts react further with tert-butylchlorodiphenylsilane to give neutral diazaphosphinines (B) which react with electron-rich acetylenes to extrude R-C≡N and form the corresponding monoazaphosphinines (For example C, Scheme 2).

References 1 See reviews: a) C. Müller, L. E. E. Broeckx, I. de Krom, J. J. M. Weemers, Eur. J. Inorg. Chem. 2013, 2013, 187–202. b) L. Kollár, G. Keglevich, Chem. Rev. 2010, 110, 4257–4302. c) C. Müller, D. Vogt, Dalton Trans. 2007, 0, 5505–5523. d) P. L. Floch, Coord. Chem. Rev. 2006, 250, 627–681; 2 Müller, C.; Wasserberg, D.; Weemers, J. J. M.; Pidko, E. A.; Hoffmann, S.; Lutz, M.; Spek, A. L.; Meskers, S. C. J.; Janssen, R. A. J.; Van Santen, R. A.; Vogt, D. Chem. Eur. J. 2007, 13, 4548–4559. 3 G. Maerkl, P. Kreitmeier, in Phosphorus-Carbon Heterocyclic Chemistry (Ed.: F. Mathey), Elsevier Science Ltd, Oxford, 2001, pp. 535–630. 4 a) G. Duret, V. Le Fouler, P. Bisseret, V. Bizet, N. Blanchard, Eur. J. Org. Chem. 2017, 2017, 6816–6830. b) C. S. Sumaria, Y. E. Türkmen, V. H. Rawal, Org. Lett. 2014, 16, 3236–3239.

Uppsala University, SWEDEN P27 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

SYNERGIC EFFECT OF MONOPHOS LIGANDS ON HYDROFORMYLATION

Hubert Meissel, Sofia Papadouli, Paul Pringle

School of Chemistry, University of Bristol, Bristol, UK e-mail: [email protected]

The hydroformylation of olefins, catalysed by rhodium complexes is largest scale industrial application of homogeneous catalysis.1 The aldehyde products are extensively used as precursors to solvents, plasticizers, pharmaceuticals and other fine chemicals. In the last five decades, many ligands have been developed to improve the regioselectivity towards the higher value linear aldehydes. The 2 hydroformylation catalyst based on Rh-PPh3 complexes has found many applications. Our focus has been on Rh catalysts based on pyrrolyl phosphines such as PPyr3 which have strongly π-accepting properties.3 We have observed a synergic effect on the hydroformylation of 1-hexene using mixtures of PPyr3 and PPh3 ligands (see Figure 1).

20

21 Selectivity l:b 10 16 12 14 5 0 0/20 5/15 10/10 15/5 20/0

Ratio of eq. PPyr3/PPh3

Figure 1: Rh-catalysed hydroformylation of 1-hexene with different ratios of PPyr3/PPh3, [Rh(acac)(CO)2] = a 0.25 mol% in (1.5 mL), CO/H2 =10/10 bars, 90 °C, [1-hexene]/[Rh] = 670, monocell autoclave. l:b determined at 30-40% of conversion by GC and NMR analysis, using internal standards decane and dodecane.

In an attempt to harness this synergic effect, the synthesis of the unsymmetrical bidentate ligand 1 based on xanthene has been carried out. The hydroformylation catalysis results obtained with Rh/1 complexes will be presented.

Acknowledgement CDT Catalysis (Cardiff UK) and EPSRC References 1 A. Behr, P. Neubert, Applied Homogeneous Catalysis, WILEY-VCH, Germany, 2011. 2 R. Franke, D. Selent, and A. Börner, Chem. Rev., 2012, 112, 5675-5732. 3 a) S. Papadouli, PhD Thesis, Bristol University, 2016. b) O. Diebolt, H. Tricas, Z. Freixa, and P. W. N. M. van Leeuwen, ACS Catal., 2013, 3, 128-137.

Uppsala University, SWEDEN P28 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Cyclic fluorophosphites: small, CO-like ligands that produce highly regioselective hydroformylation catalysts

Alexandra M. Miles-Hobbs, Eliza G. Hunt and Paul G. Pringle*

University of Bristol, Cantock’s Close, Bristol, BS8 1TS [email protected]

For half a century, phosphites have been the quintessential π-acceptor ligands which, unlike CO, have the capacity for modification.1 Since the 1980s, cyclic phosphites, particularly those featuring 7- and 8-membered phosphacycles, have been the ligands of choice for metal-complex catalysed hydroformylation (e.g. 1)2 and hydrocyanation.3

In contrast to ligands containing P-O bonds, ligands containing P-F bonds (apart from PF3) have received little attention. Despite the fact that the fluorophosphite 2 has attracted industrial interest as a ligand for hydroformylation catalysis,4 no systematic study of the organometallic chemistry of cyclic fluorophosphites has been carried out. Here, we report the synthesis and chemistry of the cyclic fluorophosphites 3-6, with particular focus on their π-acceptor and coordination properties, which are reminiscent of CO or PF3. Their application as ligands for the hydroformylation of 1-hexene is also explored; it is shown that some of these modifiable ligands display excellent regioselectivity, with n:iso ratios of up to 50:1.

Acknowledgement The authors gratefully acknowledge the EPSRC for funding. References 1. A. Gual, C. Godard, V. de la Fuente, S. Castillόn, Phosphorus (III) Ligands in Homogeneous Catalysis, 2012, 81-131. 2. J. Mayer, J. Babin, E. Billig, D. Bryant, T. Leung, US Patent, 1994, US 5288918 A. 3. M. Baker, K. Harrison, A. Orpen, P. Pringle, G. Shaw, J Chem. Soc., Chem. Commun., 1991, 803-804. 4. a) J. Rodgers, Y-S. Liu, US Patent, 2009, US 0171121 A1. b) T. Puckette, US Patent, 2007, US 7301054 B1. c) T. Puckette, G. Struck, US Patent, 1998, US 5840647 A.

Uppsala University, SWEDEN P29 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Different Hetero-Cyclopentane-1, 3-diyls Modification of molecular switches with different sterically demanding groups

Henrik Müller,a Jonas Bresien,a Dirk Michalik,a Anne-Kristin Rölke,a Axel Schulz,a,b Alexander Villinger, a Edgar Zander a

aInstitut für Chemie, Abteilung Anorganische Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany. bLeibniz-Institut für Katalyse e.V. an der Universität Rostock, Abt. Materialdesign, Albert-Einstein-Straße 29a, 18059 Rostock, Germany. [email protected], [email protected]

Biradicaloids are molecules bearing two unpaired electrons which interact considerably.[1] They display an interesting electronic structure and extraordinary properties. Over the last few decades, especially biradicaloids containing group 15 elements and different sterically demanding substituents have attracted significant attention. Recently, we reported on the synthesis of hetero-cyclopentanediyls (2, 4; Figure 2) by insertion of isonitriles into cyclodiphospadiazanediyls (1, 3).[2] In case of 2Dmp, we observed a highly selective photochemical isomerisation triggered by irradiation (Figure 1). The complete process was found to be fully reversible; hence the system can be regarded as a molecular [3] switch. To modify the properties of such compounds, for example with Figure 1. Under respect to the excitation wavelength, different sterically demanding groups irradiation with red light, can be used. Conspicuously, the hypersilylated ring system (4) undergoes a the biradicaloid 2Dmp (top) isomerized to the silyl group migration from the ring to the exocyclic nitrogen atom (4’), housane 2'Dmp (bottom). leading to a different electronic situation within the ring system that is best described as a hetero-.

N P N h P CN-R C R  P C R Ter N N Ter Ter N Ter N P P N  P N Ter Ter 1 2 2'

Hyp N N P P R P CN-R C R C Hyp N N Hyp Hyp N Hyp N N N P P Hyp P 3 4 4' Figure 2. R = tBu (tert-Butyl), Dmp (2,6-Dimethylphenyl), Mes (2,4,6-Trimethylphenyl). References [1] T. Beweries, R. Kuzora, U. Rosenthal, A. Schulz, A. Villinger, Ang. Chem. Int. Ed. 2011, 8974–8978. [2] A. Hinz, A. Schulz, A. Villinger, J. Am. Chem. Soc. 2015, 9953−9962. [3] D. Bløger, S. Hecht, Ang. Chem. Int. Ed. 2015, 11338–11349.

Uppsala University, SWEDEN P30 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

4 Investigation of the reactivity of [Cp’’’Co(η -P4)]

M. Piesch and M. Scheer University of Regensburg, Institute of Inorganic Chemistry, Universitätsstraße 31, 93053 Regensburg, Germany Email: [email protected]

There are only very few examples known for organometallic compounds containing a cyclo-P4 ligand R 4 R [1] R as an end-deck. Beside the complexes [Cp M(CO)2(η -P4)] (M = Nb, Cp = Cp*, M = Ta, Cp = [2-3] R [4] 4 Cp’’, Cp’’’, M = V, Cp = Cp* ) [Cp’’’Co(η -P4)] (1) represents the first carbonyl free compound [5] of this type. It could be synthesized by the reaction of P4 with the reactive triple decker complex 4 4 [5] [(Cp’’’Co)2(η :η -C7H8)]. The reaction of 1 with Ag[TEF] ([TEF] = Al{OC(CF3)3}4) leads to different one-dimensional polymers (2-4) dependent on the reaction conditions. The reaction of 1 with the nucleophiles NaOH 3 - 3 3 - and LiCH2SiMe3 yield [Cp’’’Co(η -P4O(H))] (5) and [(Cp’’’Co)2(µ2-η :η -P8CH2SiMe3)] (6), respectively. 1 can be reduced by K[CpFe(CO)2] to form a P8 ligand containing complex 3 3 2- [(Cp’’’Co)2(µ2-η :η -P8)] (7).

Scheme 1: Selected reactivity of 1.

References [1] O. J. Scherer, J. Vondung, G. Wolmershäuser, Angew. Chem., 1989, 101, 1395-1397. [2] O. J. Scherer, R. Winter, G. Wolmershäuser, Z. Anorg. Allg. Chem., 1993, 619, 827-835. [3] F. Dielmann, Dissertation, Universität Regensburg, 2011. [4] M. Herberhold, G. Frohmader, W. Milius, J. Organomet. Chem., 1996, 522, 185-196. [5] F. Dielmann, A. Timoshkin, M. Piesch, G. Balázs, M. Scheer, Angew. Chem., 2017, 129, 1693-1698.

Uppsala University, SWEDEN P31 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Phosphorus-containing dendrimers with peripheral P-chiral ferrocenyl phosphines

J. Popp,a A.-M. Caminade,b and E. Hey-Hawkinsa,*

aInstitute of Inorganic Chemistry, Leipzig University. Leipzig. Germany. bLaboratoire de Chimie de Coordination, CNRS. Toulouse. France. @ [email protected]

In recent catalyst development, the attention turned to homogeneous catalysts whose activity in different chemical processes can be switched by an external stimulus. Recently, our group reported on the redox control of a catalytic process, which also corroborates the power of dendritic structures in homogeneous catalysis.[1] We now have focused on introducing a P-stereogenic phosphine suitable for asymmetric induction to employ this ligand system also for homogeneous asymmetric transformations.

Employing Jugé’s ephedrine-based method,[2] several P-stereogenic monodentate ferrocenyl phosphines were synthesised with high enantiomeric excess (>95% ee in all cases). The anchoring group in the 1' position of the ferrocene derivatives allows furthermore the grafting of these P-stereogenic ferrocenyl phosphines on the surface of phosphorus-containing dendrimers developed by the research group of Caminade.[3] Consequently, the obtained P-stereogenic dendritic ferrocenyl phosphines will now be applied as ligands in asymmetric redox-switchable transition metal catalysis.

Acknowledgement The authors gratefully acknowledge the COST Action CM1302 Smart Inorganic Polymers (SIPs) for financial support. References 1 P. Neumann, H. Dib, A.-M. Caminade, E. Hey-Hawkins, Angew. Chem. 2015, 127, 316-319; Angew. Chem. Int. Ed. 2015, 54, 311-314 2 S. Jugé, M. Stephan, J. A. Laffitte, J. P. Genet, Tetrahedron Lett. 1990, 31, 6357-6360 3 N. Launay, A.-M. Caminade, J. P. Majoral, J. Organomet. Chem. 1997, 529, 51-58

Uppsala University, SWEDEN P32 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Crystalline, Room-Temperature Stable Phosphine ‒SO 2 Adducts and their Reactivity

Philipp Rotering, Florenz Buß and Fabian Dielmann*

Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster. Germany. @ [email protected]

Since the seminal work of Smith and Smith in 1965 [1] the reaction between sulfur dioxide and tertiary phosphines has been further investigated by many groups. However, stable phosphine ‒SO 2 adducts have never been observed and only phosphine oxides and phosphine sulfides were identified as degradation products. We reasoned that more electron donating phosphines should allow the isolation of a stable phosphine ‒SO 2 adduct. Therefore, we used phosphines with imidazolin-2-ylidenamino substituents for our study. These phosphines are more basic than alkylphosphines and their steric and [2] electronic properties can be easily modulated. The stability of the new SO2 adducts turned out to be in close correlation with the phosphines donor ability. NMR studies on the degradation process are reported and the first phosphine ‒SO 2 adducts were characterized by X-ray diffraction studies.

SO 2 binding by phosphines and further reactivity.

References 1 B. C. Smith, G. H. Smith, J. Chem. Soc. 1965 , 5516-5517. 2 a) P. Mehlmann, C. Mück-Lichtenfeld, T. Tan, F. Dielmann, Chem. Eur. J. 2017 , 23 , 5929-5933. b) F. Buß, P. Mehlmann, C. Mück-Lichtenfeld, K. Bergander, F. Dielmann, J. Am. Chem. Soc . 2016 , 138 , 1840-1843.

Uppsala University, SWEDEN P33 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis of a new sterically hindered phosphane

Moritz Scharnhölz,a Jonas Bresien,a José Goicoecheab, Axel Schulza Alexander Villingera

a Institut für Chemie, Universität Rostock. Albert-Einstein-Straße 3a, 18059 Rostock. Germany. b Department of Chemistry, University of Oxford. Chemistry Research Laboratory 12 Mansfield Road, Oxford OX1 3TA. United Kingdom. [email protected]

Sterical hindrance is vital for the isolation of low valent phosphorus compounds, as dimerization or oligomerization is often thermodynamically favoured over the formation of a monomeric species.1 In phosphorus chemistry, Mes* and Ter substituents are frequently utilised, but the stabilisation provided was not sufficient for the long-standing goal of obtaining the diazonium analogous [R‒PP]+ cation.2 A recent example of a sterically demanding group is MeAr* (1). Established in 2010, Guillaume Me Berthon-Gelloz used Ar*─NH2 to synthesize a highly sterically demanding N-heterocylic carbene (2).3

Our project is aimed at introducing the MeAr* moiety into phosphorus chemistry. Me Because the amine Ar*‒NH2 is readily available, it was chosen as a starting material. Subsequently, a diazotation was performed and the diazonium salt was converted to the chloride, bromide and iodide derivatives. MeAr*‒X (X = Cl, Br, I) could be obtained, isolated and fully Me characterized. Lithiation and reaction with phosphorus trichloride yielded Ar*‒PX2 (X = I, Cl). Hydrogenation with LiAlH4 resulted in the desired phosphane. The reaction can be upscaled to multi-gram-scale.

Current studies are focused on the reactivity of this phosphane and its coordination chemistry.

References 1 A. Schulz, Z. Anorg. Allg. Chem. 2014, 640, 2183-2192. 2 J. Bresien, C. Hering, A. Schulz, A. Villinger, Chem. - Eur. J. 2014, 20, 12607-12615. 3 G. Berthon-Gelloz, M. A. Siegler, A. L. Spek, B. Tinant, J. N. H. Reek, I. E. Marko, Dalton Trans. 2010, 39, 1444-1446.

Uppsala University, SWEDEN P34 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Accessing Li/Cl phosphinidenoid iron(0) complexes: Synthesis, Characterization and Reactivity

Alexander Schmer, Tatjana Terschüren and Rainer Streubel*

Institut für Anorganische Chemie, University of Bonn, Gerhard-Domagk-Str. 1 53121 Bonn, Germany, [email protected]

Over the past 10 years, the chemistry of highly reactive Li/Cl phosphinidenoid complexes was de- veloped having a clear focus on group 6 metals.[1] Starting point was the discovery of a mild and facile synthetic route based on deprotonation or (better) Cl/Li exchange at low temperatures which led selectively to the desired phosphinidenoid complexes.[1a] A variety of reactivity studies were conducted including reactions with alkyl halides,[1a] alkynes,[1a] amines,[2] alcohols,[3] aldehydes,[1a,4] and epoxides[5] resulting in a manifold of new and novel P-ligand arrays. Nevertheless the estab- lishment of new Li/Cl phosphinidenoid complexes having different transition metals represented a significant and important challenge with respect to reactivity modification.

Herein, we report on the synthesis of a new stable dichlorophosphane Fe(CO)4 complex having a sterically demanding triphenylmethyl substituent attached at the phosphorus center. With this iron complex in hands, investigations with respect to the generation of a novel Li/Cl phosphinidenoid iron complex were performed. The latter one was characterized at low temperature and the thermal stabilitiy was studied by VT NMR measurments.[6] In addition, the reactivity of the Li/Cl phosphinidenoid iron complex was tested towards amines, ammonia and water. Acknowledgement The authors gratefully acknowledge the COST action CM1302 (SIPs) and the Deutsche Forschungsgemeinschaft (STR 411/29-3). References 1 a) A. Özbolat, G. von Frantzius, J. M. Peŕez, M. Nieger, R. Streubel, Angew. Chem. 2007, 119, 9488-9491; Angew. Chem., Int. Ed. 2007, 46, 9327-9330. b) V. Nesterov, G. Schnakenburg, A. Espinosa Ferao, R. Streubel, Inorg. Chem. 2012, 51, 12343-12349. 2 a) P. K. Majhi, A. W. Kyri, A. Schmer, G. Schnakenburg, R. Streubel, Chem. Eur. J. 2016, 22, 15413-15419. b) R. Streubel, A. Schmer, A. W. Kyri, G. Schnakenburg, Organometallics 2017, 36, 1488-1495. 3 a) R. Streubel, A. W. Kyri, L. Duan, G. Schnakenburg, Dalton Trans. 2014, 43, 2088-2097. b) L. Duan, G. Schnakenburg, J. Daniels, R. Streubel, Eur. J. Inorg. Chem. 2012, 3490-3499. 4 a) C. Albrecht, M. Bode, J. M. Peŕez, J. Daniels, G. Schnakenburg, R. Streubel, Dalton Trans. 2011, 40, 2654- 2665. b) R. Streubel, M. Klein, G. Schnakenburg, Organometallics 2012, 31, 4711-4715. 5 a) A. Kyri, G. Schnakenburg, R. Streubel, Angew. Chem. 2014, 126, 10985-10988; Angew. Chem. Int. Ed. 2014, 53, 10809-10812. b) A. W. Kyri, G. Schnakenburg, R. Streubel, Organometallics 2016, 35, 563-568. 6 A. Schmer, A. Doddi, N. Volk, G. Schnakenburg, A. Espinosa, R. Streubel, to be published.

Uppsala University, SWEDEN P35 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

12-Vertex zwitterionic bis-phosphonium-nido-carborates via ring- opening reaction of 1,2-diphosphetanes

Jan Schulz,a Anika Kreienbrink,a and Evamarie Hey-Hawkinsa,*

aFaculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Leipzig University. Leipzig. Germany [email protected]

We have previously reported several syntheses incorporating the cleavage of the P–P bond in 1,2- diphosphetanes (1) by reaction with lithium, followed by addition of HCl[1] or dichlorophosphines[2] to give access to open-chain or cyclic derivatives. In case of 1a, the lithiated intermediate, [{1- PtBuLi(THF)-6-PtBu-4,1,6-closo-Li(THF)C2B10H10}{Li(THF)3}]2∙2 THF (2a) could be isolated and structurally characterised (Scheme 1). The compound is dimeric, C2-symmetric and contains six lithium and four phosphorus atoms. Two lithium ions are capping the six-membered C2B4 faces resulting in two 13-vertex closo-clusters (according to Wade's rules) with docosahedral geometry.[3] Addition of MeI gave the zwitterionic bis-phosphonium-nido-carborates, 7,10-bis(tert-butyl- dimethylphosphonium)-dodecahydro-7,10-dicarba-nido-dodecaborate(2–) (3a). Additionally, 7,10- bis(N,N-diisopropylamino-dimethylphosphonium)-dodecahydro-7,10-dicarba-nido-dodecaborate(2–) (3b) was obtained in a similar fashion, when 3b was used as a starting material. 3a and 3b exhibit short [3] CclusterP bonds and large Ccluster∙∙∙Ccluster distances in the solid state.

Scheme 1. Synthetic routes incorporating the cleavage of Scheme 2. Synthesis of zwitterionic nido-12-vertex bis- the P–P bond in 1a with elemental lithium with formation phosphonium carborates 3a,b via ring-opening reaction of the lithiated intermediate 2a.[1,2] and methylation of carborane-based 1,2-diphosphetanes 1a,b.[3] Acknowledgement Support from the Studienstiftung des deutschen Volkes (doctoral grant for J.S.), the Konrad-Adenauer Stiftung (doctoral grant for A.K.) and the Graduate School Leipzig School of Natural Sciences – Building with Molecules and Nano-objects (BuildMoNa) is gratefully acknowledged. References 1 A. Kreienbrink, P. Lönnecke, M. Findeisen, E. Hey-Hawkins, Chem. Commun. 2012, 48, 9385–9387. 2 A. Kreienbrink, S. Heinicke, T. T. D. Pham, R. Frank, P. Lönnecke, E. Hey-Hawkins, Chem. Eur. J. 2014, 20, 1434–1439. 3 J. Schulz, A, Kreienbrink, P. Coburger, B. Schwarze, T. Grell, P. Lönneck, E. Hey-Hawkins, Chem. Eur. J. 2018, 24, in print (DOI: 10.1002/chem.201800172).

Uppsala University, SWEDEN P36 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis and characterization of 1-phoshaenyne analogue of 1,3- -3-yne

Muhammad A. Shameem, Andreas Orthaber*.

Department of chemistry Ångström, Uppsala University, 75120 Uppsala, Sweden. [email protected]

Enynes are structural motif found in natural products and a crucial synthetic precursor for many complex organic reactions.[1] [2] [3] Herein we describe Pd/Cu mediated synthesis of conjugated 1- phospha-1,3-butadiene-3-yne. Our group recently showed the construction of a cross-conjugated [4] motif, diacetylenic phosphaalkene, starting from Mes*P=C(Br)2 using metal free conditions. Subsequently, the resultant diacetylenic phosphaalkene can undergo an in situ addition reaction in the presence of Pd, CuI, a suitable base and excess of acetylene. This unexpected 1-phospha-1,3- butadiene-3-yne has been fully characterized by NMR and X-ray crystallography. Preliminary investigation of crucial mechanistic step has been followed by 31P-{H}-NMR which indicates pre coordination of Pd[0] to the phosphorus center followed by addition of Cu acetylides.

Figure 1: General reaction scheme

References [1] D. John Faulkner, Nat. Prod. Rep. 2001, 18, 1R–49R. [2] H. Villar, M. Frings, C. Bolm, Chem. Soc. Rev. 2007, 36, 55–66. [3] Y. Hu, M. Bai, Y. Yang, Q. Zhou, Org. Chem. Front. 2017, 4, 2256–2275. [4] M. A. Shameem, K. Esfandiarfard, E. Öberg, S. Ott, A. Orthaber, Chem. – Eur. J. 2016, 22, 10614–10619.

Uppsala University, SWEDEN P37 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Soliccoccozyma terricola- new yeast strain with glyphosate degrading activity.

Natalia Stosieka, Agata Terebieniecb, Hubert Cieślińskib, Adam Ząbeka, Magdalena Klimek-Ochaba

aDepartment of Bioorganic Chemistry, Wrocław University of Science and Technology. Wrocław. Poland. bDepartment of Molecular Biotechnology and Microbiology, Gdańsk University of Technology. Gdańsk. Poland. @ email: [email protected]

Abstract N-phosphonomethylglycine (glyphosate, PMG), an active component of the popular, non-selective herbicide Roundup, inhibits the activity of the 5-enol-pyruvyl-shikimate-3- synthase (EPSPS; [E.C 2.5.1.19]), which is part of the shikimate pathway responsible for aromatic amino acids biosynthesis.1 PMG degradation can occurs in two main ways, both leading to C-P bond cleavage. P-C bond cleavage due to the C-P lyase complex activity is a pathway that is more commonly found in both prokaryotic and eukaryotic organisms. Second pathway is based on glyphosate oxidoreductase (GOx) activity which catalyses C-N bond cleavage in PMG to form aminomethylphosphonic acid (AMPA) and glyoxylate.2,3 Up to now decomposition of herbicide via GOx activity has not been proven in eukaryotic organisms. A novel psychrophilic yeast strain capable of N-phosphonomethylglycine mineralization as the sole phosphorus, nitrogen and phosphorus-nitrogen source was isolated from soils of the Arctowski Polish Antarctic Station. Secretion of inorganic phosphate to culture medium confirmed the progress of the glyphosate biodegradation process, suggesting that the strain degrades the herbicide in an independent manner of the phosphate cell status. So far, this way of PMG biodegradation has been proven only for two bacterial strains4,5 and S.terricola is the first eukaryotic strain with this capacity. GOx activity was detectable in cell-free extracts prepared from S. terricola pregrown on 4 mM PMG as sole phosphorus and nitrogen source. It is the first example of a psychrophilic yeast strain which degrading PMG accompanied by AMPA formation via C-N bond cleavage and not like in most microorganisms via C-P bond breakage. 31P NMR analysis confirmed the presence of PMG in the culture medium after 6 days of cultivation and LC-MS analysis confirmed the presence of AMPA and 60% loss of substrate. S. terricola may have a potential application for the bioremediation of glyphosate contaminated soils and isolation of relevant genes may be used to construct herbicide- resistant plants in the future. Acknowledgement The work was financed by a statutory activity subsidy from the Polish Ministry of Science and Higher Education for the Faculty of Chemistry of Wrocław University of Science and Technology.

References 1 E. Schonbrun, S. Eschenburg, W.A. Shuttleworth, J.V. Schloss, N. Amrheim, J.N.S Evans, W. Kabsch, PNAS, 98, 1376-1380, 2001 2 P. Kafarski, B. Lejczak, G. Forlani, Amer. Chem. Soc., Symp. Ser. 777, 145-163, 2001 3 R. Pipke, N. Amrhein, G.S. Jacob, J. Schaefer, G.M. Kishore, Eur. J. Biochem., 165, 267-273, 1987 4 A. Obojska, B. Lejczak, M. Kubrak, Appl. Mirobiol. Biotechnol., 51(6), 872-876, 1977 5 G.F. Barry, In Biosynthesis and Molecular Regulation of Amino Acids in Plants, ASPB, 139-145, 1992

Uppsala University, SWEDEN P38 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Cationic Phosphonium Containing ROMP Based Antibacterial Copolymers

Naime Ceren SÜER,a Ali BAYIR,a Mehmet Mücahit GÜNCÜ,b Burak AKSUb and Tarık ERENa,* a Chemistry Department, Yıldız Technical University. İstanbul. Turkey. b Medical Microbiology Department, Marmara University. İstanbul. Turkey. [email protected]

Phosphorus containig materials have a wide variety of industrial applications such as dispersants, corrosion inhibiting agent and flame retardancy. Recently, they have been found to be effective for biomedical applications as well, such as dentistry, drug delivery and tissue engineering [1]. Phosphorus containing cationic polymers are also shown to have antimicrobial properties similar to well known cationic amonium polymers. However, when phosphonium and ammonium salts were synthesized with the same hydrophobic structure, it was observed that the phosphonium salts showed an advantage over the corresponding ammonium salts in bactericidal activity and killing rate [2]. Previously, we synthesized various phosphonium salt containing homopolymers and measured their antibacterial activities [3]. In this study, ROMP (ring opening metathesis polymerization) was used for the preparation of phosphonium based copolymers as a controlled polymerization technique. We made copolymers of two sets of homopolymers which have low MIC90 value, low hemolytic concentration (HC50) and high MIC90 value, high HC50. Thus, we hope to obtain polymers with low MIC90 value and high HC50.

Scheme.1: Polymers synthesized and used in this study

Acknowledgement The authors gratefully acknowledge the TUBITAK 113S355 and COST action CM1302 (SIPs). References 1. S. Monge, B. Canniccioni, A. Graillot, J.J. Robin, Biomacromolecules 2011, 12, 1973–1982. 2. A. Kanazawa, T. Ikeda, T. Endo, Antimicrob. Agents Chemother. 1994, 38, 945-952. 3. N.C. Süer, C. Demir, N.A. Ünübol, O Yalçın, T. Kocagöz, T. Eren, RSC Advances 2016, 6, 86151-86157.

Uppsala University, SWEDEN P39 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Diphosphanes with diversified substituents Synthesis, classification and stereochemistry

Natalia Szynkiewicz,a Łukasz Ponikiewskia and Rafał Grubbaa

aDepartment of Inorganic Chemistry, Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland [email protected]

Diphosphanes are trivalent phosphorus compounds with P-P bond of the general formula R1R2P-PR3R4, belonging to class of polyphosphorus compounds. Type of substituents bound with phosphorus atoms determine stereochemistry, chemical and spectroscopic properties of these systems. In the present work we have reviewed method of synthesis unsymmetrical diphosphanes, finding out that manipulation of the reaction conditions enables obtaining this compounds in a good yield and high purity without usage of intermediate boron adducts as previously reported.1,2 Applying this approach, we have synthetized a set of eighteen novel unsymmetrical alkyl(amine)- substituted diphosphanes of the general formula R1R2P-PR3R4 (where R1, R2, R3, R4 = tBu, Ph, Et2N or iPr2N), with substituents differ in electron-donating and steric properties. All compounds have been characterized by NMR, X-ray and DFT methods in order to investigate the influence of the type of substituents bound with phosphorus atoms on structure and nucleophilic properties of obtained diphosphanes. Moreover, a simple general classification of such systems on the basis of number of different substituents attached to phosphorus atoms and their distribution within a molecule was proposed.

Acknowledgement N.S. and R.G. thank the National Science Centre NCN, Poland (Grant 2016/21/B/ST5/03088) for financial support. N.S thanks the TASK Computational Centre For for access to computational resources References 1 D. L. Dodds, M. F. Haddow, A. G. Orpen, P. G. Pringle and G. Woodward, Organometallics, 2006, 25, 5937– 5945. 2 D. L. Dodds, J. Floure, M. Garland, M. F. Haddow, T. R. Leonard, C. L. McMullin, A. G. Orpen and P. G. Pringle, Dalt. Trans., 2011, 40, 7137–7146.

Uppsala University, SWEDEN P40 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Electrochemical Oxidation of the Heavier Group 15 Cyanate Analogues PCO− and AsCO−

Frank Tambornino, Eden E. L. Tanner, Richard G. Compton and Jose M. Goicoechea *

Department of Chemistry, University of Oxford, Oxford. [email protected]

The 2-phosphaethynolate anion (PCO−) was first reported in 1992 and the 2-arsaethynolate (AsCO−) in 2016.[1] Improved synthetic access of PCO− has recently sparked systematic investigations into the [2] chemistry of this anion. Here we report on the electrochemical behaviour of [Na(dioxane)x]PCO in water and acetonitrile, and [Na(dioxane)x]AsCO in acetonitrile. Initial cyclic voltammetry experiments indicated severe poisoning of the electrodes after only one cycle. Possible surface modifications of the electrodes were examined by cycling glassy carbon electrodes in the electrolytes, gently washing the surfaces with acetonitrile and subsequent imaging of the surfaces with scanning electron microscopy. Cycling of a solution containing [Na(dioxane)x]AsCO resulted in electrodeposition of elemental arsenic as agglomerated spheres with 30–100 nm diameter. EDX analysis confirms the deposits to be pure elemental arsenic, corroborating the suggested oxidation mechanism of AsCO−, depositing arsenic and evolving CO gas. Scan rate studies (scan rates from 10–1000 mV s−1) and subsequent Tafel analysis revealed the respective diffusion coefficients for the anions in question. 31P Diffusion Oriented Nuclear Magnetic Resonance Spectroscopy (DOSY) independently confirmed the diffusion coefficients of the PCO anion in water (1.8 × 10-9 m2s-1) and acetonitrile (2.3 × 10-9 m2s-1), respectively.

From left to right: Scan rate study of [Na(dioxane)x]PCO in water. Scan rate study [Na(dioxane)x]AsCO acetonitrile. Recorded SEM image of As-deposits obtained after electrochemical cycling of NaAsCO solution on a glassy carbon electrode. Acknowledgement The authors gratefully acknowledge the Deutsche Forschungsgemeinschaft DFG (TA 1357/1-1) and the European Research Council (European Union’s Seventh Framework Programme (FP/2007-2013/ERC Grant Agreement no. [320403]) for financial support. We thank Hatem Amin for recording SEM micrographs and EDX mappings, and Prof. Tim Claridge for help with DOSY measurements.

References 1 a) G. Becker, W. Schwarz, N. Seidler, M. Westerhausen, Z. Anorg. Allg. Chem. 1992, 612, 72-82. b) A. Hinz, J. M. Goicoechea, Angew. Chem. Int. Ed. Engl. 2016, 55, 8536–8541. 2 M. Westerhausen, S. Schneiderbauer, H. Piotrowski, M. Suter, H. Nöth, J. Organometalic Chem. 2002, 643– 644, 189–193.

Uppsala University, SWEDEN P41 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Imidazoliumyl-substituted dipyrazolylphosphanes as P1-precursor for for the synthesis of polyphosphanes

Clemens Taube,a Kai Schwedtmann,a David Harting,a Felix Hennersdorf,a Robert Wolf,b Jan J. Weiganda

aChair of Inorganic Molecular Chemistry, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01069 Dresden, Germany. bInstitute of Inorganic Chemistry, Universität Regensburg, 93040 Regensburg, Germany. [email protected]

In the course of our research with focus on the synthesis of new polyphosphorous compounds, we aim to further extend the existing protocol of condensation reactions of pyrazolyl-substituted phosphanes.[1] Herein, we report the use of imidazoliumyl-substituted chlorophosphanes as [2] P1-precusors.

Scheme 1: Synthesis of dipyrazolylphosphanes 3[OTf] and 4[OTf]. The reaction of cationic chlorophosphanes 1[OTf] or 2[OTf] with silylated 1,3-dimethyl-pyrazol leads to the formation of the imidazoliumyl-substituted dipyrazolylphosphanes 3[OTf] and 4[OTf] (Scheme 1). Due to the reactive P–N bond, these novel cationic dipyrazolylphosphanes can be used in condensation reactions with different secondary phosphanes for the formation of polyphosphorous compounds.

Scheme 2: Synthesis of Triphosphane 7[OTf] and of 1,2,3-Triphospholanes 8[OTf] and 9[OTf]. Compound 4[OTf] selectively forms the triphosphane 7[OTf] in a two-stage condensation with diphenylphosphane and diphenylpyrazolylphosphane. The use of 1,2-bis(phenylphosphanyl)ethane[3] leads to the 1,2,3-triphospholanes 8[OTf] and 9[OTf] via a condensation reaction (Scheme 2). The aforementioned compounds serve well as cationic ligands for transition metal complexes. Acknowledgement We thank the German Science Foundation (DFG, grant number WE 4621/3-1) for financial support. References 1 a) K.-O. Feldmann, R. Fröhlich, J. J. Weigand, Chem. Commun. 2012, 48, 4296; b) K.-O. Feldmann, J. J. Weigand, J. Am. Chem. Soc. 2012, 134, 15443. 2 a) F. D. Henne, A. T. Dickschat, F. Hennersdorf, K.-O. Feldmann, J. J. Weigand, Inorg. Chem. 2015, 54, 6849; b) K.-O. Feldmann, J. J. Weigand, Angew. Chem. Int. Ed. 2012, 51, 6566 – 6568. 3 Issleib, K.; Weichmann, H. Chem. Ber. 1968, 101, 2197.

Uppsala University, SWEDEN P42 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

3H-Phosphaallenes -Synthesis and Reactivity-

Jonas Christian Tendycka, Hans Klöckera, Werner Uhla

aInstitut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität, Münster, Germany. [email protected]

Hydroalumination of supermesityl substituted dialkynylphosphines with sterically less shielded ethylaluminum hydride affords masked FLPs which decompose to yield various stable 3H-phosphaallenes. The chemical driving force is the elimination of dimeric dialkyl aluminium alkynides.1 Although few of these 3H-phosphaallenes have been known for a long time, their crystal structures were unknown up to now, and there is only little knowledge on their chemical reactivity.2 With this new facile method we are able to isolate these compounds in high yields in a multigram scale, to determine their crystal structures and to investigate their chemical properties.

Beside of stable 3H-phosphaallenes this route opend access to instable 3H-phosphaallenes which have sterically smaller substituents at the phosphorus atoms like mesityl, triisopropylphenyl or bis(trimethylsilyl)methyl (Bis). For the generation of less shielded 3H-phosphallenes it is important to use sterically higher shielded dialkylaluminiumhydrides to inhibit the reaction of the masked FLPs with the 3H-phosphaallens.3 These 3H-phosphaallenes are highly interesting of their secondary reactions such as dimerization to diphosphines. Instable 3H-phosphaallenes can be isolated and purified by complexation with metal carbonyls like the W(CO)5-fragment.

References 1 H. Westenberg, J. C. Slootweg, A. Hepp, J. Kösters, S. Roters, A. W. Ehlers, K. Lammertsma, W. Uhl, Organometallics 2010, 29, 1323. 2 R. Appel, V. Winkhaus, F. Knoch, Chem. Ber. 1986, 119, 2466; G. Märkl, U. Herold, Tetrahedron Lett. 1988, 29, 2935; M. Yoshifuji, S. Sasaki, N. Inamoto, Tetrahedron Lett. 1989, 30, 839. 3 H. Klöcker, S. Roters, A. Hepp, W. Uhl, Dalton Trans. 2015, 44, 12670.

Uppsala University, SWEDEN P43 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Alcoholysis of dialkyl phosphites in a continuous flow microwave reactor

Nóra Tóth*, Ádám Tajti, Erika Bálint and György Keglevich

Department of Organic Chemistry and Technology, Budapest University of Technology and Economics. Budapest. Hungary [email protected]

The microwave (MW) technique has many benefits as compared to conventional heating [1]. Although, the scale up of MW-assisted reactions is limited by the geometry of magnetron, and by the problem of the structural material. To solve this difficulty, continuous flow MW reactors should be used [2]. In our research, we have developed a continuous flow MW system, comprising a batch MW reactor, equipped with a commercially available flow cell, and integrated with an HPLC pump [3].

The alcoholysis of dialkyl phosphites (1) was examined in the absence of any catalyst under MW conditions. In the first step, batch experiments were carried out, then the reactions were transferred into over continuous flow MW reactor. Depending on the temperature and the flow rate (or the residence time), the mixed esters (2) or the fully transesterified products (3) were obtained as predominant product.

Acknowledgement

SUPPORTED THROUGH THE NEW NATIONAL EXCELLENCE PROGRAM OF THE MINISTRY OF HUMAN CAPACITIES

References 1 E. Bálint, G. Keglevich; The Spread of the Application of the Microwave Technique in Organic Synthesis, In: Keglevich, G. (ed.) Milestones in Microwave Chemistry, Switzerland: Springer International Publishing, 2016, pp. 1-10. 2 I. Baxendale, J. Hayward, S. Ley, Combinatorial Chemistry & High Throughput Screening 2007, 10, 802-836. 3 Á. Tajti, N. Tóth, E. Bálint, G. Keglevich, Esterification of benzoic acid in a continuous flow microwave reactor. J. Flow. Chem. 2017 – in press.

Uppsala University, SWEDEN P44 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis of α-Aminophosphine Oxide Derivatives Kabachnik-Fields and "click" reactions

Anna Tripolszky,*a Erika Bálinta and György Keglevicha

aDepartment of Organic Chemistry and Technology, Budapest University of Technology and Economics, Budapest, Hungary [email protected]

In a broader sense, α-aminophosphine oxides are the structural analogues of α-amino acids. Due to their versatile bioactivity, they have attracted much attention.1 A few of their derivatives may be potential P(III)-ligands.2 One of the most convenient and widespread method for the synthesis of α-aminophosphine oxides is the Kabachik-Fields (phospha-Mannich) reaction, which is based on the condensation of an amine, an aldehyde or ketone, and a >P(O)H species, such as a secondary phosphine oxide.3 We studied the microwave (MW)-assisted catalyst-free synthesis of α-aminophosphine oxides. The utilization of the products obtained was also investigated.4 Different secondary phosphine oxides were synthesized by the Grignard reaction, and applied in single and double Kabachnik-Fields condensation under MW conditions. In the first approach, the reaction of primary amines was studied with one equivalent of paraformaldehyde and one equivalent of secondary phosphine oxides. The aminophosphine oxides prepared were converted to asymmetric N,N-bis(phosphinoylmethyl)amines. Other double Kabachnik–Fields condensations were also investigated. In these cases, the primary amines were reacted with two equivalents of paraformaldehyde and the P-reagents. The reactions were carried out in the absence of any catalyst, and the products were obtained in excellent yields.

After double deoxygenation, the symmetric and asymmetric bis(phosphine oxides) so obtained were transformed to ring platinum(II) and palladium(II) complexes. The Pt(II) complexes were tested as catalysts in the hydroformylation of styrene. side-chain containing triazoles were also synthesized by CuI-catalyzed "click" reactions. Acknowledgement The authors gratefully acknowledge the Hungarian Research Development and Innovation Fund (FK123961 and K119202). References 1 Hanessian, S.; Bennani, Y.L. Synthesis 1994, 12, 1272-1274. 2 Jana, R.; Pathak, T. P.; Sigman, S. M. Chemical Reviews 2011, 111, 1417-1492. 3 a) Kabachnik, M. I.; Medved, T. Y. Dokl. Akad. Nauk SSSR. 1952, 83, 689-692. b) Fields, E. K. J. Am. Chem. Soc. 1952, 74, 1528-1531. c) Keglevich, G.; Bálint, E. Molecules 2012, 17, 12821-12835. 4 Bálint, E.; Tripolszky, A.; Jablonkai, E.; Karaghiosoff, K.; Czugler, M.; Mucsi, Z.; Kollár, L.; Pongrácz, P.; Keglevich, G. J. Organomet. Chem. 2016, 801, 111-121.

Uppsala University, SWEDEN P45 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

SYNTHESIS OF FLUORINATED PHOSPHONIC ANALOGUES OF PHENYLALANINE

Weronika Wanat1, Jean-Luc Pirat2, Paweł Kafarski1

1 Department of Bioorganic Chemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland 2 AM2N, Institut Charles Gerhardt, UMR 5253, ENSCM, 8, rue de l’Ecole Normale, 34296 Montpellier, France e-mail: [email protected]

Aminophosphonates constitute a unique class of compounds of bioorganic chemistry and medicinal interest. As analogues of natural amino acids, these compounds possess ability to influence physiological and pathological processes through inhibition of enzymes, which play a crucial role in cell metabolism especially of proteases1. Due to the essential properties of phenylalanine in living organisms (it is primarily functioning as building block for proteins)2 their phosphonic counterparts have been synthesized. Most frequently they act as inhibitors of aminopeptidases. Phosphonic analogues of phenylalanine, bearing different number of fluorine atoms and other substituents in the phenyl ring, have been synthesized by modified and optimized multistep reaction, described by Maier and Diel3 (Fig.1). The structures of intermediates, products and side-products were determined by means of 1H NMR, 13C NMR, 19F NMR, 31P NMR and ESI-MS.

Fig.1. Preparation of α-aminophosphonic acid analogues of phenylalanine.

Acknowledgement The authors gratefully acknowledge the COST action by a statutory activity subsidy from the Polish Ministry of Science and Education for the Faculty of Chemistry of Wrocław University of Science and Technology. References 1 a) B. Lejczak, P. Kafarski, Top. Heterocycl. Chem. 2009, 20, 31–63, b) A. Mucha, P. Kafarski, Ł. Berlicki, J. Med. Chem. 2011, 54, 5955-5980, c) F. Orsini, G. Sello, M. Sisti, Curr. Med. Chem. 2010, 17, 264–289. 2 M. J. O'Neil (ed.), Whitehouse Station, NJ: Merck and Co., Inc., 2006, 1255. 3 a) L. Maier, P. Diel, Phosphorus, Sulfur and Silicon, 1991, 62, 15-27, b) L. Maier, P. Diel, Phosphorus, Sulfur and Silicon, 1994, 90, 259-279, c) M. Drąg, J. Grembecka, M. Pawełczak, P. Kafarski, European Journal of Medicinal Chemistry 2005, 40, 764-771.

Uppsala University, SWEDEN P46 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

The preparation of optically active acyclic phosphine oxides by resolution

Bence Varga,a Péter Bagi,a Elemér Fogassya and György Keglevicha

aDepartment of Organic Chemistry and Technology, Budapest University of Technology and Economics, Budapest, Hungary. [email protected]

The main application of enantiopure P-chiral phosphines involves their utilization as ligands of transition metal complexes [1,2]. Compounds containing P-stereogenic center cannot be found in the natural pool of chirality, therefore their enantiomers can only be prepared by asymmetric synthesis or resolution [2]. Previously, our research group developed an efficient resolution method for the enantiomeric separation of P-chiral phosphine oxides applying TADDOL-derivatives and the Ca2+-salt of tartaric derivatives as resolving agents. However, these methods have only been applied in the sphere of P-heterocyclic phosphine oxides [3]. In this study, it was investigated whether these resolution methods are of more general value. Therefore, we extended these resolution methods to dialkyl-aryl- (1a), diaryl-alkyl- (1b) and triarylphosphine oxides (1c). First, the corresponding P-chiral model compounds were prepared in racemic form. The resolution of the phosphine oxides (1) was then elaborated with TADDOL- derivatives (2 and 3) or with the acidic Ca2+-salts of the (R,R)-O,O’-dibenzoyl- and (R,R)-O,O’-di-p-toluoyl-tartaric acid (4 and 5). The main parameters influencing the overall efficiency of the resolution procedures were also examined. Moreover, a correllation was found between the efficiency of the resolution and molecular sturcture. In case of the diaryl-alkylphosphine oxide (1b), the purification and the racemization possibilities of the enantiomeric mixtures of the optically active phosphine oxide were also investigated [4].

Acknowledgement This work was supported by the National Research, Development and Innovation Office - NKFIH (Grant No. OTKA PD 116096). The publication of the work reported herein has been supported by ETDB at BME. References 1 M. Dutartre, J. Bayardon, S. Jugé, Chem. Soc. Rev. 2016, 45, 5771-5794 2 A. Grabulosa, P-Stereogenic Ligands in Enantioselective Catalysis, The Royal Society of Chemistry: Cambridge 2010 3 P. Bagi, V. Ujj, M. Czugler, E. Fogassy, G. Keglevich, Dalton Trans. 2016, 45, 1823-1842 4 P. Bagi, B. Varga, A. Szilágyi, K. Karagiosoff, M. Czugler, E. Fogassy, G. Keglevich, Chiraliy, 2018, DOI: 10.1002/chir.22816

Uppsala University, SWEDEN P47 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Reactivity of Pentelidene Complexes with aromatic Amines and Isocyanides

Rudolf Weinzierl a and Prof. Dr. Manfred Scheer a

aInstitute of Inorganic Chemistry, University of Regensburg. Regensburg. Germany [email protected] , [email protected]

Phosphinidenes (IUPAC: phosphanylidenes) are low valent organophosphorus compounds. Our research is focused on the reactivity of bridging pentelidene complexes of the type [Cp*E{W(CO) 5}2] (E = P, As; Cp* = C 5Me 5). These complexes show interesting reaction behavior under thermolytic [1] and photolytic [2] conditions. In addition they are good electrophiles and therefore, they can easily be attacked by different nucleophiles such as primary phosphines. [3] The reactivity of these pentelidene complexes towards primary amines and isocyanides will be presented. Sterically demanding isocyanides form stable Lewis acid/base adducts [4] like compounds 2a and 2b . Compound 4 is formed with less bulky isocyanides but an excess of isocyanide is needed. The reaction towards primary amines yields the aminopentelidene complexes 3a , 3b , and 3c .

Figure 1 : Reactivity of the pentelidene complexes [Cp*E{W(CO) 5}2] (E = P, As) towards amines and isonitriles

References 1 M. Scheer, E. Leiner, P. Kramkowski, M. Schiffer, G. Baum, Chem. Eur. J . 1998 , 4, 1917-1923. 2 M. Scheer, C. Kuntz, M. Stubenhofer, Michael Linseis, Rainer F. Winter, Marek Sierka, Angew. Chem. Int. Ed. 2009 , 48 , 2600-2604. 3 M. Scheer, C. Kuntz, M. Stubenhofer, M. Zabel, A. Y. Timoshkin, Angew. Chem. 2010 , 122 , 192-196. 4 M. Seidl, M. Schiffer, M. Bodensteiner, A. Y. Timoshkin, M. Scheer, Chem. Eur. J. 2013 , 19 , 13783-13791.

Uppsala University, SWEDEN P48 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

CO2 Capture and Conversion with Phospines

Lukas Wilm, a Tobias Eder,a Paul Mehlmann,a Florenz Bußa and Fabian Dielmannc,*

aInstitut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität. Münster. Germany. [email protected]

For the efficient utilization of carbon dioxide as feedstock in chemical synthesis, low-energy barrier CO2 activation plays a crucial role. Our approach to reversible CO2 binding under mild conditions is based on simple Lewis base adducts with imidazolin-2-ylidenamino-substituted phosphines (IAPs).[1] These electron rich phosphines (IAPs) can be easily modulated by their electronic and steric properties due to their substitution pattern as well as the backbone of their substituents. This enables the modification of the IAPs donor ability which correlates with the stability of the corresponding zwitterionic CO2 adducts. The strongest electron donor in this series, tris(imidazoline-2-ylidenamino)phosphine P(NIiPr)3, is [2] capable of cleaving a CO bond of CO2. Furthermore, the efficiency of CO2 capture compared to other metal free systems was studied by microfluidic methods.[3]

Figure 1. Tolman Electronic Parameter (TEP) values of different phosphines and their respective reactivity towards CO2.

References

1 F. Buss, P. Mehlmann, C. Mueck-Lichtenfeld, K. Bergander, F. Dielmann, J. Am. Chem. Soc. 2016, 138, 1840-1843. 2 P. Mehlmann, C. Mück-Lichtenfeld, T. T. Y. Tan, F. Dielmann, Chem. Eur. J. 2017, 23, 5929-5933. 3 J. J. Chi, T. C. Johnstone, D. Voicu, P. Mehlmann, F. Dielmann, E. Kumacheva, D. W. Stephan, Chem. Sci. 2017, 8, 3270- 3275.

Uppsala University, SWEDEN P49 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

An Isolable Phosphaethynolatoborane and Its Reactivity

Daniel W. N. Wilson,a Alexander Hinz,a Jose M. Goicoechea.a*

a Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, OX1 3TA, Oxford, UK @ [email protected]

The 2-phosphaethynolate anion, PCO― , is a phosphorus-containing analogue of cyanate (NCO― ) first reported in 1992 by Becker and co-workers.1 Recent improvements in its synthesis has led to increased interest in this species.2 As with the cyanate ion, the 2-phosphaethynolate anion is ambiphilic, capable of binding to Lewis acids through either the phosphorus (as a phosphaketenyl moiety) or the oxygen (as a phosphaethynolato moiety). To date, the former bonding mode has dominated metal and main-group PCO― chemistry,3 while the phosphaethynolato mode has only been structurally authenticated in the coordination sphere of uranium, thorium and scandium.4 We reasoned that to access a stable phosphaethynolato compound, the best course of action would be to employ an electropositive main-group element with strong oxophilic character. For this purpose we decided to employ a salt-metathesis strategy utilising a bulky bromoborane. Here, we report the synthesis of the first isolable phosphaethynolatoborane and explore its reactivity towards lithiated reagents and transition metals.

Acknowledgement We thank the EPSRC and the University of Oxford for financial support of this research (EP/M027732/1 and DTA studentship D.W.N.W.). References 1 G. Becker, W. Schwarz, N. Seidler, M. Westerhausen, Z. Anorg.Allg. Chem. 1992, 612, 72 – 82. 2 D. Heift, Z. Benko, H. Grutzmacher, Dalton Trans. 2014, 43, 831 – 840. 3 a) S. Alidori, D. Heift, G. Santiso-Quinones, Z. Benko, H. Grützmacher, M. Caporali, L. Gonsalvi, A. Rossin, M. Peruzzini, Chem. Eur. J. 2012, 18, 14805 – 14811; b) L. Liu, D. A. Ruiz, F. Dahcheh, G. Bertrand, R. Suter, A. M. Tondreau, H. Grützmacher, Chem. Sci. 2016, 7, 2335 – 2341; c) S. Yao, Y. Xiong, T. Szilvasi, H. Grützmacher, M. Driess, Angew. Chem. Int. Ed. 2016, 55, 4781– 4785; d) L. Liu, D. A. Ruiz, D.Munz, G. Bertrand, Chem. 2016, 1, 147 – 153; 4 a) C. Camp, N. Settineri, J. Lefevre, A. R. Jupp, J. M. Goicoechea, L. Maron, J. Arnold, Chem. Sci. 2015, 6, 6379 – 6384; b) C. J. Hoerger, F. W. Heinemann, E. Louyriac, L. Maron, H.Grützmacher, K. Meyer, Organometallics. 2017, 36, 4351 – 4354; c) L. N. Grant, B. Pinter, B. C. Manor, H. Grützmacher, D. J. Mindiola, Angew. Chem. Int. Ed. 2018, 57, 1049 – 1052.

Uppsala University, SWEDEN P50 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Ligand Design for Improved Alkoxycarbonylation Understanding and Application for Enhanced Proton Transfer

Kevin B. Vincent,a Sarah J. Williams,a Andrei S. Batsanov,a Matthew L. Clarke,b Simon K. Beaumont,a and Philip W. Dyer*,a

aDepartment of Chemistry, Durham University. Durham. UK. b Department of Chemistry, Univerity of St Andrews. St Andrews. Scotland. [email protected]

Carbonyl compounds are among the most ubiquitous starting materials in organic chemistry. (CO) has been used for their preparation since the 1930s when Roelens reported the hydroformylation of alkenes to aldehydes.1 Subsequently, industrial carbonylation reactions have become the largest application of homogeneous catalysis, such as the carbonylation of methanol to produce acetic acid via the Monsanto2 or Cativa3 processes. Specifically, alkoxycarbonylation of ethylene to afford methyl propionate is widely used in the production of methylmethacrylate (MMA) via the Lucite Alpha process.4 Recent work by Drent and co-workers suggested incorporation of a hemi-labile pyridyl group on the ligand scaffold can help to control selectivity and activity,5 the work of Beller and co workers has shown such architectures can be used to give high selectivity for linear methoxycarbonylation of tri- and tetra-substituted alkenes.6 To further study and extend the understanding of these processes, we have prepared a range of different Pd-diphosphine complexes, with and without the pyridyl functionality at the ligand, but containing amine functionality in the ligand backbone (see figure 1) for catalytic testing in alkoxycarbonylation reactions.

Figure 1: Representative example of Pd-diphosphine complexes containing amine functionalized backbones

Acknowledgement The authors gratefully acknowledge the UK’s EPSRC Catalysis Hub for funding. References 1. W. Reppe, Liebigs Ann. Chem., 1953, 582, 1 2. D. Forster, Adv. Organomet. Chem., 1979, 17, 255 3. A. Haynes, et. al, J. Am. Chem. Soc., 2004, 126, 2847 4. G. Eastham, P. Cameron, R. Tooze, K. Cavell, P. Edwards and D. Coleman, WO2004014552A1, 2004 5. L.Crawford, D.J. Cole-Hamilton, E. Drent and M. Bühl, Chem. Eur. J, 2014, 20, 13923 6. K. Dong, et. al., Nat. Commun, 2017, 8, 14117

Uppsala University, SWEDEN P51 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Cytotoxic Ruthenium-Diphosphine Complexes

Dan Wise,a Paul Pringle,a Jason Lynam,b Paul Waltonb a School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, UK b Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK [email protected]

Following the success of cisplatin and other platinum-containing anticancer drugs, ruthenium coordination complexes represent a promising class of metal-containing pharmaceuticals.1 Three ruthenium complexes that display greater cytotoxicity and reduced side effects compared to cisplatin are in advanced clinical trials.2 A range of ruthenium-diphosphine complexes have been tested in vitro against cancer cell lines. The ruthenium precursor is readily prepared from 1,3,5- triaminocyclohexane (tach) which coordinates in a tridentate, facially capping manner, leaving two labile dmso ligands. These are substituted by diphospine ligands to give novel ruthenium-tach diphosphine complexes, (Figure 1, A).

Figure 1. A) Synthesis of ruthenium-tach precursor and single crystal X-ray structure. B) Chemical structures of selected diphosphines.

This work builds on earlier results from Lynam et al3 (Figure 1, B). By adding a fluorescent probe to the ligand, we aim to study the different modes of action of ruthenium complexes on cancer cells, and develop structure-activity-relationships. References (1) Motswainyana, W. M.; Ajibade, P. A. Adv. Chem. 2015, 1. (2) Leijen, S.; Burgers, S. A.; Baas, P.; Pluim, D.; Tibben, M.; van Werkhoven, E.; Alessio, E.; Sava, G.; Beijnen, J. H.; Schellens, J. H. M. Invest. New Drugs. 2015, 33, 201. (3) Gamble, A. J.; Lynam, J. M.; Thatcher, R. J.; Walton, P. H.; Whitwood, A. C. Inorg. Chem. 2013, 52, 4517.

Uppsala University, SWEDEN P52 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Gold(I) complexes with bulky, electron-rich imidazolin-2- ylidenaminophosphines

Tim Witteler, Fabian Dielmann*

Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster [email protected]

Imidazolin-2-ylidenaminophosphines (IAPs) are strong electron-donating ancillary ligands. Their donor strength and steric demand can be modified by the choice of substituents at the imidazole backbone.[1] In this contribution aryl substituents where employed at the imidazole nitrogen atoms to create a steric profile resembling that of the Buchwald-type phosphines (Figure 1). This sterically demanding IAPs where coordinated to gold(I) chloride and used in catalytic hydroamination reaction. The stability of cationic gold(I) complexes was examined by means of DFT calculations. The IAPs show similar properties like Buchwald ligands, but with higher donor strength, thus broadening the spectrum of available sterically demanding phosphine ligands.

Figure 1. Left: TEP values of PPh3, PtBu3, dialkyl aryl phosphines and NHCs compared to dialkyl imidazolin-2-ylidenaminophosphines. Right: molecular structure of a di-tert-butyl-imidazolin-2- ylidenaminophosphine gold(I) complex.

References 1 Wünsche, M. A.; Mehlmann, P; Witteler, T; Buß, F.; Rathmann, P.; Dielmann, F., Angew. Chem. Int. Ed. 2015, 11857.

Uppsala University, SWEDEN P53 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

2-Trimethylsilylphosphinines: [4+2]-Cycloaddition of 2-Pyrones with Trimethylsilylphosphaalkyne

Friedrich Wossidlo,a Marija Habichta and Prof. Dr. Christian Müllera,*

aInstitute of Chemistry and Biochemistry, Freie Universität Berlin. Berlin. Germany. [email protected]; [email protected]

Rösch and Regitz reported on the [4+2]-cycloaddition reaction between 2-pyrones (1) and tBu-C≡P under formation of 2-(tert-butyl)-λ3-phosphinines. The reaction allows the synthesis of low-substituted phosphinines, while the nature of the ortho-substituent is limited by the choice of the corresponding .1 We recently described the use of TMS-C≡P2 (2) in this reaction, which gives access to rather air- and moisture stable 2-(trimethylsilyl)-λ3-phosphinines (3). Due to the properties of the trimethylsilyl group, the low-coordinate phosphorus heterocycle can be further modified, for example, by means of C-C-coupling or protodesilylation reactions.3

Scheme 1: [4+2]-Cycloaddition reaction between 2-pyrones (1) and TMS-C≡P (2).3 Insight into the regioselectivity of the pericyclic reaction was obtained with the help of deuterium-labeling experiments. We could also show that the reaction with TMS-C≡P (2) proceeds significantly faster compared to tBu-C≡P.3 The facile access to 3-bromo-2-pyrone allows the preparation of 6-bromo-2-trimethylsilyl- phosphinine (3a) for the first time. The bromophosphinine 3a quantitatively undergoes Negishi cross-coupling reactions with diffrent arylzinc compounds (4). Several phosphinines of the types 3 and 5 could be synthesized and characterized by means of X-ray diffraction of the corresponding transition-metal complexes.3

Scheme 2: Negishi cross-coupling of 6-bromo-2-trimethylsilylphosphinine (3a).3

Acknowledgement The authors gratefully acknowledge the Freie Universität Berlin and the DFG for their financial support. References 1 W. Rösch, M. Regitz, Z. Naturforschung B 1986, 41, 931−933. 2 M. Mansell, M. Green, R. J. Kilby, M. Murray, C. A. Russel, C. R. Chim. 2010, 13, 1073−1081. 3 a) M. Habicht, F. Wossidlo, M. Weber, C. Müller, Chem. Eur. J. 2016, 22, 12877−12883; b) M. Habicht, F. Wossidlo, T. Bens, E. A. Pidko, C. Müller, Chem. Eur. J. 2018, 24, 944−952.

Uppsala University, SWEDEN P54 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Synthesis of New Polyphosphido Cobalt Complexes by P‒P Condensation

Christoph Ziegler,a Thomas Maier,a Stefan Pelties,a Anup Kumar Adhikari,a Clemens Taube,b Prof. Dr. Jan J. Weigand,b* and Prof. Dr. Robert Wolfa* a University of Regensburg, Institute of Inorganic Chemistry, 93040 Regensburg, Germany. b TU Dresden, Department of Chemistry and Food Chemistry, 01062 Dresden, Germany. [email protected]

Transition metal complexes are potentially attractive tools for harnessing white phosphorus (P4) as a [1] resource for new (poly)phosphorus compounds. However, the selectivity of P4 activation process can be difficult to control, and the resulting neutral polyphosphido complexes are often not sufficiently reactive. These challenges inspire ongoing research efforts towards generating new reactive transition metal polyphosphido complexes from P4.

Herein, we illustrate the little-explored concept of heterobimetallic P4 activation by reporting the 4 2 synthesis and reactivity of [K(dme)2(BIAN)Co(µ-η :η -P4)(Ga{nacnac})] (1, BIAN = [N,N′-Bis(2,4,6- trimethylphenl)imino]acenaphthene, nacnac = [N,N′-Bis(2,6-diisopropylphenyl)-2,4-pentanediimine]) 2 [2] obtained by the reaction of cobaltate anion with Ga(nacnac)(η -P4). Condensation reactions of 1 with R2PCl (R = tBu, iPr, and Cy) afforded new polyphosphido complexes [(BIAN)Co(cyclo-P5R2)] (2). Several intermediates were detected by 31P{1H} NMR spectroscopy, including 3 characterized by X-ray crystallography.

References [1] a) B. M. Cossairt, N. A. Piro, C. C. Cummins, Chem. Rev. 2010, 110, 4164; b) M. Caporali, L. Gonsalvi, A. Rossin, M. Peruzzini, Chem. Rev. 2010, 110, 4178; c) M. Peruzzini, R. R. Abdreimova, Y. Budnikova, A. Romerosa, O. J. Scherer, H. Sitzmann, J. Organomet. Chem. 2004, 689, 4319; d) M. Peruzzini, L. Gonsalvi, A. Romerosa, Chem. Soc. Rev. 2005, 34, 1038. [2] a) F. Hennersdorf, J. Frötschel, J. J. Weigand, J. Am. Chem. Soc. 2017, 139, 14592; b) G. Prabusankar, A. Doddi, C. Gemel, M. Winter, R. A. Fischer, Inorg. Chem., 49, 7976; c) S. Pelties, T. Maier, D. Herrmann, B. d. Bruin, C. Rebreyend, S. Gärtner, I. G. Shenderovich, R. Wolf, Chem. Eur. J. 2017, 23, 6094.

Uppsala University, SWEDEN P55 European Workshop on Phosphorus Chemistry - EWPC 15/2018 March 14-16

Titanium and low-valent phosphorus chemistry. The reactivity study of titanium(III) complexes with phosphanylphosphido ligand.

Aleksandra Ziółkowska,a Łukasz Ponikiewski,a Jerzy Pikies,a

a Department of Inorganic Chemistry, Faculty of Chemistry, Gdansk University of Technology, 11/12 Gabriela Narutowicza Street, 80-233 Gdansk, Poland. e-mail: [email protected]

The reports number of metal-phosphorus systems is growing every year and this motivated us to study more elaborated ligands systems containing P-P bond. The synthesis and reactivity of A B transition metal complexes with phosphanylphosphido [R R P-P(SiMe3)] and phosphanyl- phosphinidene [RARBP-P] ligands is intensively studied in our group. Initially a lot of attention was focused on reactivity research of late transition metals such as Pt, Pd, Ni [1-3] but recently we have intensively studied synthesis and properties of phosphanylphosphido and phosphanylphosphinidene complexes with early transition metals, especially titanium complexes. [4,5]

Preliminary investigations of titanium(III) phosphanylphosphido complexes [NacnacTi(Cl){ɳ2- A B A B P(SiMe3)-PR R }] (where R = tBu, iPr; R = tBu, iPr, Ph) were conducted for: - nucleophilic reagents; in reactions with R”Li (R” = Ph2P, N(SiMe3)2, tBuO, NtBu2) in a presence of 12-Crown-4 we have obtained new ionic complexes with titanium(III); - electrophilic reagents; the reactivity research with RCRDPCl allowed us to study the new synthesis route to obtain the phosphanylphosphinidene complexes with different, symmetrical (RC = RD) and asymmetrical substituents RC and RD on phosphanyl phosphorus atom.

Acknowledgement The authors gratefully acknowledge the National Science Centre for Grant Harmonia, (No. 2012/06/M/ST5/00472).

References 1 H. Krautscheid, E. Matern, G. Fritz, J. Pikies, Z. Anorg. Allg. Chem. 1998, 624, 1617-1621. 2 A. Wiśniewska, K. Baranowska, R. Grubba, E. Matern, J. Pikies, Z. Anorg. Allg. Chem. 2010, 636, 1549- 1556. 3 E. Baum, E. Matern, A. Robaszkiewicz, J. Pikies, Z. Anorg. Allg. Chem. 2006, 632,1073-1077. 4 Ł. Ponikiewski, A. Ziółkowska, J. Pikies, Inorg. Chem. 2017, 56, 1094-1103. 5 Ł. Ponikiewski, A. Ziółkowska, M. Zauliczny, J. Pikies, Polyhedron, 2017, 137, 182–187.

Uppsala University, SWEDEN P56