DOCSLIB.ORG

Formation of Active Species from Ruthenium Alkylidene Catalysts-An

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Formation of Active Species from Ruthenium Alkylidene Catalysts-An Journal of Molecular Modeling (2019) 25: 331 https://doi.org/10.1007/s00894-019-4202-5 ORIGINAL PAPER Formation of active species from ruthenium alkylidene catalysts—an insight from computational perspective PawełŚliwa1 & Mariusz P. Mitoraj2 & Filip Sagan2 & Jarosław Handzlik1 Received: 27 July 2019 /Accepted: 3 September 2019 /Published online: 7 November 2019 # The Author(s) 2019 Abstract Ruthenium alkylidene complexes are commonly used as olefin metathesis catalysts. Initiation of the catalytic process requires formation of a 14-electron active ruthenium species via dissociation of a respective ligand. In the present work, this initiation step has been computationally studied for the Grubbs-type catalysts (H2IMes)(PCy3)(Cl)2Ru=CHPh, (H2IMes)(PCy3)(Cl)2Ru=CH- CH=CMe2 and (H2IMes)(3-Br-py)2(Cl)2Ru=CHPh, and the Hoveyda-Grubbs-type catalysts (H2IMes)(Cl)2Ru=CH(o- OiPrC6H4), (H2IMes)(Cl)2Ru=CH(5-NO2–2-OiPrC6H3), and (H2IMes)(Cl)2Ru=CH(2-OiPr-3-PhC6H3), using density function- al theory (DFT). Additionally, the extended-transition-state combined with the natural orbitals for the chemical valence (ETS- NOCV) and the interacting quantum atoms (IQA) energy decomposition methods were applied. The computationally determined activity order within both families of the catalysts and the activation parameters are in agreement with reported experimental data. The significance of solvent simulation and the basis set superposition error (BSSE) correction is discussed. ETS-NOCV dem- onstrates that the bond between the dissociating ligand and the Ru-based fragment is largely ionic followed by the charge delocalizations: σ(Ru–P) and π(Ru–P) and the secondary CH…Cl, CH…π,andCH…HC interactions. In the case of transition state structures, the majority of stabilization stems from London dispersion forces exerted by the efficient CH…Cl, CH…π,and CH…HC interactions. Interestingly, the height of the electronic dissociation barriers is, however, directly connected with the prevalent (unfavourable) changes in the electrostatic and orbital interaction contributions despite the favourable relief in Pauli repulsion and geometry reorganization terms during the activation process. According to the IQA results, the isopropoxy group in the Hoveyda-Grubbs-type catalysts is an efficient donor of intra-molecular interactions which are important for the activity of these catalysts. Keywords Density functional theory . Natural orbitals for chemical valence . Extended-transition-state . Grubbs catalysts . Hoveyda-Grubbs catalysts . Olefin metathesis This paper is dedicated to Professor Zdzisław Latajka, honouring his significant contribution to quantum chemistry. Introduction This paper belongs to the Topical Collection Zdzisław Latajka 70th Birthday Festschrift Well-defined ruthenium alkylidene complexes (Fig. 1)are Electronic supplementary material The online version of this article commonly used as highly efficient catalysts for olefin metath- (https://doi.org/10.1007/s00894-019-4202-5) contains supplementary esis. These systems show a high tolerance towards most of the material, which is available to authorized users. functional groups in the substrates, air and moisture insensi- tivity, and thermal stability [1–4]. * Mariusz P. Mitoraj The key step during the olefin metathesis process is initial [email protected] formation of a 14-electron active complex [5–14]. In the case * Jarosław Handzlik of the Grubbs-type catalysts (1–3), it occurs by dissociation of [email protected] ligands L, whereas for the Hoveyda-Grubbs catalysts (4–6), it requires decoordination of the ether moiety (Fig. 2). Electron 1 Faculty of Chemical Engineering and Technology, Cracow University of Technology, ul. Warszawska 24, and steric properties of these ligands significantly affect the 31-155 Kraków, Poland rate of the catalyst activation [6–8, 10–12, 14, 15]. In addition 2 Department of Theoretical Chemistry, Faculty of Chemistry, to this often postulated dissociative mechanism, where the Jagiellonian University, ul. Gronostajowa 2, 30-387 Kraków, Poland dissociation/decoordination is the first step, associative and 331 Page 2 of 15 J Mol Model (2019) 25: 331 Fig. 1 Example ruthenium alkylidene catalysts interchange mechanisms for the activation of the second and rate-determining step [12]. For the Grubbs-type catalysts, the third generation ruthenium alkylidene catalysts were also pro- dissociative mechanism was rather computationally predicted posed [8, 9, 12, 14, 16, 17]. In the case of the associative as the kinetically favoured one, with the dissociation step be- mechanism, the alkene molecule coordinates to the metal cen- ing rate determining [12, 17]. Calculations also showed that tre before dissociation of the appropriate ligand, whereas for the Gibbs energy barrier for phosphine dissociation from the the interchange mechanism, both steps take place simulta- Grubbs complex is solvent- and entropy-related [18]. neously. Experimental kinetic studies for the Hoveyda- In this work, the formation of the propagating 14-electron Grubbs catalysts indicated that two mechanisms, dissociative alkylidene species from the Grubbs-type (1–3) and Hoveyda- and interchange, are in work, depending on the steric and Grubbs-type (4–6) initiators has been investigated using den- electronic properties of the ruthenium complex and the sub- sity functional theory (DFT). Our main objectives are to com- strate employed [8]. Accordingly, the dissociative pathway pare the activation parameters for catalysts with different li- was theoretically shown to be preferred over the interchange gands within a given family of compounds and to analyse in one in the case of the Hoveyda-Grubbs complexes bearing a detail the nature of the interactions between the dissociating large chelating alkoxy ligand, although the Hoveyda ligand ligand L and the rest of the system. Bonding between the decoordination during the cross-metathesis reaction is the ligand L and the remaining Ru-based fragment is R NN N N 1 Mes Mes -L Mes Mes Cl Cl R Ru Ru 1 Cl R +L Cl R L R N N Mes N N Mes Mes Mes Cl Cl Ru Ru Cl Cl R1 R1 N N Mes Mes Mes N N Mes R' Cl Cl Ru Ru O Cl Cl R R 1 O 2 R2 R R Fig. 2 Mechanism of olefin metathesis catalysed by ruthenium alkylidene complexes [7] J Mol Model (2019) 25: 331 Page 3 of 15 331 characterized for catalysts 1–3 and the corresponding transi- It is well-established that the ground state for 16- tion state structures, using the extended-transition-state meth- electron and 14-electron ruthenium alkylidene complexes, od combined with the natural orbitals of the chemical valence studied in this work, is singlet [18, 42]. According to the (ETS-NOCV) [19–22]. The Hoveyda-Grubbs catalysts have PBE0/def2-SVP calculations, the triplet and quintet states been additionally characterized by means of the interacting of the 16-electron complex 1 are less stable than the sin- quantum atoms (IQA) [23] energy decomposition. This is glet state, by 93 and 191 kJ mol−1, respectively. In the the first time when these complementary theoretical ap- case of the 14-electron species 1_dis, formed after disso- proaches (ETS-NOCVand IQA) are used to get deeper insight ciation of 1, the corresponding differences are 75 and into formation of active species from olefin metathesis 171 kJ mol−1. Hence, the spin-restricted formalism is used catalysts. for other computations. Furthermore, the DFT approach was proved sufficiently accurate in studying the reactivity of ruthenium alkylidene complexes [12, 13, 18, 28–33]. However, it shall be noticed, that for more difficult cases Computational methods (e.g., open-shell transition metal complexes), single- determinant DFT shall be applied with special caution Geometry optimization of all structures was carried out using due to the approximated character of electron correlation, the hybrid GGA PBE0 functional [24] combined with the as well as a possible multireference character of split-valence def2-SVP basis set [25]. The 28 innermost elec- wavefunction. trons of Ru were replaced by the Stuttgart effective core po- All the above calculations were done with the Gaussian 09 tential [26]. Further single point energy calculations were per- software [43]. formed with the hybrid meta-GGA M06 functional [27]and For the Grubbs type catalysts, the charge and energy de- the triple-zeta valence def2-TZVPP basis set [25, 26]. The composition ETS-NOCV [19, 20] analysis was performed. M06 method is recommended for main-group and transition DFT (BLYP [44, 45]) calculations were carried out with the metals thermochemistry, kinetics, and studies of noncovalent Amsterdam Density Functional (ADF) program [21, 22], in interactions [27]. A good performance of the M06 functional which the ETS-NOCV scheme was implemented. The pre- in predicting energies of reactions involving ruthenium sented energies include DFT-D3(BJ) dispersion corrections alkylidene complexes [28–33], including the dissociation en- [46, 47]. The standard triple-zeta STO basis set containing ergy for the Grubbs catalysts [28–31], was proved and it was one set of polarization functions (TZP) was used for the ru- often used for investigations of real ruthenium systems thenium atom, whereas the double-zeta basis set (DZP) was [28–36]. On the other hand, the PBE0 method was shown to employed for other elements as implemented in the ADF [21, be accurate in reproducing experimental geometry of the sec- 22]. The contours of deformation densities were plotted based ond generation Grubbs catalyst (1)[28, 37], being even better on the ADF-GUI
Load more

Recommended publications
  • Olefin Metathesis in Aqueous Media Offers a New, Broad M
    Green Chemistry CRITICAL REVIEW View Article Online View Journal | View Issue Olefin metathesis in aqueous media Cite this: Green Chem., 2013, 15, 2317 Jasmine Tomasek and Jürgen Schatz* The worldwide undisputable and unattainable chemist is nature, using water as a solvent of choice in biosynthesis. Water as a solvent not only indicates “green chemistry” but is also inevitable in biochemical reactions as well as syntheses of several pharmaceutical products. In the last few decades, several organic reactions were successfully carried out under aqueous conditions, a powerful and attractive tool in Received 3rd June 2013, organic synthesis metathesis reaction. This review summarises advances made in metathesis reaction in Accepted 12th July 2013 aqueous media. Two main strategies can be distinguished: the design of water soluble catalysts to obtain DOI: 10.1039/c3gc41042k homogeneous conditions and using commercially available catalysts to utilize the advantages of hetero- www.rsc.org/greenchem geneous conditions. reactions, meaning coupling reactions of cyclic and acyclic Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Introduction alkenes or alkynes as well as polymerisation reactions In organic chemistry, C–C coupling reactions open a wide (Scheme 1).1 Accordingly, the metathesis has been of great range of applications for effective synthesis, which otherwise interest since its discovery in the mid-1950s3 and reveals a would be difficult or even hardly feasible. The olefin meta- powerful tool for both industrial applications,
    [Show full text]
  • Hoveyda–Grubbs Catalysts with an N→Ru Coordinate Bond in a Six-Membered Ring
    Hoveyda–Grubbs catalysts with an N→Ru coordinate bond in a six-membered ring. Synthesis of stable, industrially scalable, highly efficient ruthenium metathesis catalysts and 2-vinylbenzylamine ligands as their precursors Kirill B. Polyanskii1, Kseniia A. Alekseeva1, Pavel V. Raspertov1, Pavel A. Kumandin1, Eugeniya V. Nikitina1, Atash V. Gurbanov2,3 and Fedor I. Zubkov*1 Full Research Paper Open Access Address: Beilstein J. Org. Chem. 2019, 15, 769–779. 1Organic Chemistry Department, Faculty of Science, Peoples’ doi:10.3762/bjoc.15.73 Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation, 2Centro Received: 23 October 2018 de Química Estrutural, Instituto Superior Técnico, Universidade de Accepted: 25 February 2019 Lisboa, Av. Rovisco Pais, 1049–001 Lisbon, Portugal and 3Organic Published: 22 March 2019 Chemistry Department, Baku State University, Z. Xalilov Str. 23, Az 1148 Baku, Azerbaijan This article is part of the thematic issue "Progress in metathesis chemistry III". Email: Fedor I. Zubkov* - [email protected] Guest Editors: K. Grela and A. Kajetanowicz * Corresponding author © 2019 Polyanskii et al.; licensee Beilstein-Institut. License and terms: see end of document. Keywords: CM; cross metathesis; Hoveyda–Grubbs catalyst; olefin metathesis; RCM; ring-closing metathesis; ring-opening cross metathesis; ROCM; ruthenium metathesis catalyst; styrene; 2-vinylbenzylamine Abstract A novel and efficient approach to the synthesis of 2-vinylbenzylamines is reported. This involves obtaining 2-vinylbenzylamine ligands from tetrahydroisoquinoline by alkylation and reduction followed by the Hofmann cleavage. The resultant 2-vinylbenzyl- amines allowed us to obtain new Hoveyda–Grubbs catalysts, which were thoroughly characterised by NMR, ESIMS, and X-ray crystallography.
    [Show full text]
  • Recent Advances in Total Synthesis Via Metathesis Reactions
    SYNTHESIS0039-78811437-210X © Georg Thieme Verlag Stuttgart · New York 2018, 50, 3749–3786 review 3749 en Syn thesis I. Cheng-Sánchez, F. Sarabia Review Recent Advances in Total Synthesis via Metathesis Reactions Iván Cheng-Sánchez Francisco Sarabia* Department of Organic Chemistry, Faculty of Sciences, University of Málaga, Campus de Teatinos s/n. 29071- Málaga, Spain [email protected] Received: 16.04.2018 ly explained by the emergence, design, and development of Accepted after revision: 30.05.2018 powerful catalysts that are capable of promoting striking Published online: 18.07.2018 DOI: 10.1055/s-0037-1610206; Art ID: ss-2018-z0262-r transformations in highly efficient and selective fashions. In fact, the ability of many of them to forge C–C bonds be- Abstract The metathesis reactions, in their various versions, have be- tween or within highly functionalized and sensitive com- come a powerful and extremely valuable tool for the formation of car- pounds has allowed for the preparation of complex frame- bon–carbon bonds in organic synthesis. The plethora of available cata- lysts to perform these reactions, combined with the various works, whose access were previously hampered by the lim- transformations that can be accomplished, have positioned the me- itations of conventional synthetic methods. Among the tathesis processes as one of the most important reactions of this centu- myriad of recent catalysts, those developed and designed to ry. In this review, we highlight the most relevant synthetic contributions promote metathesis reactions have had a profound impact published between 2012 and early 2018 in the field of total synthesis, reflecting the state of the art of this chemistry and demonstrating the and created a real revolution in the field of total synthesis, significant synthetic potential of these methodologies.
    [Show full text]
  • Dissertation Reactivity and Selectivity in The
    DISSERTATION REACTIVITY AND SELECTIVITY IN THE POLYMERIZATION OF MULTIFUNCTIONAL ACRYLIC MONOMERS BY CHIRAL ZIRCONOCENIUM CATALYSTS Submitted by Fernando Vidal Peña Department of Chemistry In partial fulfillment of the requirements For the Degree of Doctor of Philosophy Colorado State University Fort Collins, Colorado Summer 2017 Doctoral Committee: Advisor: Eugene Y.-X. Chen Richard G. Finke Steven Strauss Ellen Fisher David Wang Copyright by Fernando Vidal Peña 2017 All Rights Reserved ABSTRACT REACTIVITY AND SELECTIVITY IN THE POLYMERIZATION OF MULTIFUNCTIONAL ACRYLIC MONOMERS BY CHIRAL ZIRCONOCENIUM CATALYSTS Described in this dissertation are the results of investigating the reactivity and selectivity in the polymerization of multifunctional acrylic monomers by chiral cationic zirconocenium catalysts. The unprecedented precision polymer synthesis method developed in this workthe polymerization of polar divinyl monomers that is not only living but also simultaneously chemoselective and stereoselectivehas enabled the synthesis of well-defined highly stereoregular functionalized polymers bearing reactive C=C bonds on every chiral repeat unit. Thus, under ambient conditions, chiral ansa-ziroconocenium catalysts of the appropriate symmetry (C2- vs CS-ligated) have afforded highly isotactic and highly syndiotactic double-bond- carrying polymers, respectively, with controlled molecular weights and narrow dispersities. The enantiomorphic-site controlled, conjugate-addition coordination polymerization mechanism is responsible for the observed
    [Show full text]
  • Ruthenium Olefin Metathesis Catalysts
    Ruthenium Olefin Metathesis Catalysts: Tuning of the Ligand Environment Ruthenium olefine metathese katalysatoren: Optimalisatie van de ligandsfeer Nele Ledoux Promotor: Prof. Dr. F. Verpoort Proefschrift ingediend tot het behalen van de graad van Doctor in de Wetenschappen: Scheikunde Vakgroep Anorganische en Fysische Chemie Vakgroepvoorzitter: Prof. Dr. S. Hoste Faculteit Wetenschappen 2007 ii Members of the Dissertation Committee: Prof. Dr. F. Verpoort Prof. Dr. Ir. C. Stevens Dr. V. Dragutan Dr. R. Drozdzak Dr. R. Winde Prof. Dr. Ir. D. Devos Prof. Dr. J. Van der Eycken Prof. Dr. P. Van Der Voort Prof. Dr. K. Strubbe This research was funded by the Fund for Scien- tific Research - Flanders (F.W.O.-Vlaanderen). Acknowledgments This dissertation is the final product of an educative and fascinating journey, which involved many contributors. First of all, I wish to express my gratitude to the people with whom I learned how to do research. There is my promotor Prof. Dr. Francis Verpoort who gave me the opportunity to join his ’Catalysis group’ and ensured the necessary funding. I’m especially grateful for his confidence and indulgence. In addition, I have been extremely lucky to work with several nice colleagues. Thank you, Thank you (= double thank you ♥) to Bart who helped me conquer many small and big difficulties, and by doing so, contributed a lot to the results reported here. Special thanks to Hans for many funny moments and support over the years. Of course, my acknowledgments also go to the other boys: Carl, Stijn, David, Jeroen, Prof. Dr. Pascal Van Der Voort and not to forget Siegfried, Steven, and Mike for the pleasant working atmosphere and supportive chats.
    [Show full text]
  • • Both Schrock and Grubbs Type Alkene Metathesis Catalysts Have a Low Coordination Number CN = 4 (After Dissociation of Pcy By
    • Both Schrock and Grubbs type alkene metathesis catalysts have a low coordination number CN = 4 (after dissociation of PCy 3 by Grubbs catalyst) • This allows facile access of the alkene to the central metal centre, where the decisive coordination step occurs. • Spectator ligands such as imido or oxo functions commonly found in metathesis catalysts promote formation of the metallacyclic intermediates. PCy 167o 3 Cl Ru P Cl Ph PCy3 Grubbs (1995) PCy3 Tolerance of functional groups in substrate (CO, OH, NH) Selectivity towards sterically unhindered olefins and strained olefins Tri- and tetra-substituted olefins are not attacked 16 Cross Metathesis (CM) • Cross metathesis has been used in industry in the form of the Shell higher olefin process (SHOP) since 1977. • This process is a combination of oligomerization, isomerization, and metathesis steps. α • First, linear C 4 to C 30+ -olefin chains are produced from ethylene. Enrichment of the C 8 – C18 fraction, which is of interest for application in various productions, is possible by a heterogeneous cross -metathesis reaction. 17 • Cross metathesis has only found limited applications however due to product “branching”. • Grubbs reported that heterodimers are obtained in high yield when one of the starting olefins first undergoes homodimerization. 18 Ring Closing Metathesis (RCM) • Ring closing metathesis is today considered a standard method in any organic synthesis laboratory (high dilution is required for diffusion controlled RCM to avoid CM). • Its suitability for the preparation of N-heterocycles has inspired natural product synthesis. • Assymetric ring closing metathesis (ARCM) has also been developed. 19 Ring Opening Metathesis (ROM) • Ring opening metathesis is the reversal of ring closing metathesis.
    [Show full text]
  • Hydrogenation of a Diene-Based Polymer Latex Hydrierung Eines Dien-Basierten Polymer-Latex Hydrogénation D’Un Latex Polymère À Base De Diène
    (19) TZZ __T (11) EP 2 676 971 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) Int Cl.: of the grant of the patent: C08C 19/02 (2006.01) C08F 36/04 (2006.01) 08.04.2015 Bulletin 2015/15 C08F 236/12 (2006.01) C08F 8/04 (2006.01) (21) Application number: 12173165.7 (22) Date of filing: 22.06.2012 (54) Hydrogenation of a diene-based polymer latex Hydrierung eines dien-basierten Polymer-Latex Hydrogénation d’un latex polymère à base de diène (84) Designated Contracting States: (56) References cited: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB EP-A1- 2 289 621 US-A1- 2006 211 827 GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR • DATABASE COMPENDEX [Online] ENGINEERING INFORMATION, INC., NEW YORK, (43) Date of publication of application: NY, US; 3 October 2011 (2011-10-03), 25.12.2013 Bulletin 2013/52 KONGPARAKUL S ET AL: "Metathesis hydrogenation of natural rubber latex", (73) Proprietor: UNIVERSITY OF WATERLOO XP002689385, Database accession no. Waterloo, Ontario N2L 3G1 (CA) E20113714322330 -& KONGPARAKUL S ET AL: "Metathesis hydrogenation of natural rubber (72) Inventors: latex", APPLIED CATALYSIS A: GENERAL, vol. • REMPEL, Garry L. 405, no. 1-2, 3 October 2011 (2011-10-03), pages Waterloo, Ontario N2T 2H4 (CA) 129-136, XP002690182, ELSEVIER NLD DOI: • PAN, Qinmin 10.1016/J.APCATA.2011.07.039 Waterloo, Ontario N2T 2W9 (CA) • DATABASE COMPENDEX [Online] • Wu, Jialong ENGINEERING INFORMATION, INC., NEW YORK, Waterloo, Ontario N2L 4N2 (CA) NY, US; 15 April 2008 (2008-04-15), MINGOTAUD •LIU,Yin A-F ET AL: "Characterization of the micellar ring Mississauga, Ontario L5B 0E8 (CA) opening metathesis polymerization in water of a norbornene derivative initiated by Hoveyda- (74) Representative: Hollah, Dorothee Grubbs’ catalyst", XP002689386, Database Isenbruck Bösl Hörschler LLP accession no.
    [Show full text]
  • Ruthenium-Based Olefin Metathesis Catalysts Bearing Ph-Responsive Ligands: External Control of Catalyst Solubility and Activity" (2011)
    The University of Southern Mississippi The Aquila Digital Community Dissertations Spring 5-2011 Ruthenium-Based Olefin Metathesis Catalysts Bearing pH- Responsive Ligands: External Control of Catalyst Solubility and Activity Shawna Lynn Balof University of Southern Mississippi Follow this and additional works at: https://aquila.usm.edu/dissertations Part of the Chemistry Commons Recommended Citation Balof, Shawna Lynn, "Ruthenium-Based Olefin Metathesis Catalysts Bearing pH-Responsive Ligands: External Control of Catalyst Solubility and Activity" (2011). Dissertations. 693. https://aquila.usm.edu/dissertations/693 This Dissertation is brought to you for free and open access by The Aquila Digital Community. It has been accepted for inclusion in Dissertations by an authorized administrator of The Aquila Digital Community. For more information, please contact [email protected]. The University of Southern Mississippi RUTHENIUM-BASED OLEFIN METATHESIS CATALYSTS BEARING PH-RESPONSIVE LIGANDS: EXTERNAL CONTROL OF CATALYST SOLUBILITY AND ACTIVITY by Shawna Lynn Balof Abstract of a Dissertation Submitted to the Graduate School of The University of Southern Mississippi in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy May 2011 ABSTRACT RUTHENIUM-BASED OLEFIN METATHESIS CATALYSTS BEARING PH-RESPONSIVE LIGANDS: EXTERNAL CONTROL OF CATALYST SOLUBILITY AND ACTIVITY by Shawna Lynn Balof May 2011 Sixteen novel, Ru-based olefin metathesis catalysts bearing pH responsive ligands were synthesized. The pH-responsive groups employed with these catalysts included dimethylamino (NMe2) modified NHC ligands as well as N-donor dimethylaminopyridine (DMAP) and 3-(o-pyridyl)propylidene ligands. These pH- responsive ligands provided the means by which the solubility and/or activity profiles of the catalysts produced could be controlled via acid addition.
    [Show full text]
  • Pyridine-Stabilized Fast-Initiating Ruthenium Monothiolate Catalysts for Z-Selective Olefin Metathesis
    This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. Article pubs.acs.org/Organometallics Pyridine-Stabilized Fast-Initiating Ruthenium Monothiolate Catalysts for Z‑Selective Olefin Metathesis Giovanni Occhipinti,* Karl W. Törnroos, and Vidar R. Jensen* Department of Chemistry, University of Bergen, Allegateń 41, N-5007 Bergen, Norway *S Supporting Information ABSTRACT: Pyridine as a stabilizing donor ligand drastically improves the performance of ruthenium monothiolate catalysts for olefin metathesis in comparison with previous versions based on a stabilizing benzylidene ether ligand. The new pyridine- stabilized ruthenium alkylidenes undergo fast initiation and reach appreciable yields combined with moderate to high Z selectivity in self-metathesis of terminal olefins after only a few minutes at room temperature. Moreover, they can be used with a variety of substrates, including acids, and promote self- metathesis of ω-alkenoic acids. The pyridine-stabilized ruthe- nium monothiolate catalysts are also efficient at the high substrate dilutions of macrocylic ring-closing metathesis and resist temperatures above 100 °C during catalysis. ■ INTRODUCTION Chart 1. Examples of Z-Selective Catalysts Transition-metal-catalyzed olefin metathesis is a powerful, versatile, and green method for making carbon−carbon double bonds and is widely used in organic synthesis.1,2 This reaction is also exploited in several industrial processes ranging from value- added processes of simple alkenes to the synthesis of complex pharmaceuticals.3,4 Grubbs-type ruthenium-based catalysts have been the most widely used so far because, in addition to their high activity, they tolerate many functional groups, including alcohols and carboxylic acids.5 Moreover, they are relatively robust toward air and moisture and therefore also easy to handle and store.
    [Show full text]
  • Decomposition of Ruthenium Olefin Metathesis Catalyst
    catalysts Review Decomposition of Ruthenium OlefinOlefin Metathesis CatalystMetathesis Catalyst Magdalena Jawiczuk 1,, Anna Anna Marczyk Marczyk 1,21,2 andand Bartosz Bartosz Trzaskowski Trzaskowski 1,* 1,* 1 1 CentreCentre of of New New Technologies, Technologies, University University of of Warsaw, Warsaw, Banacha Banacha 2c, 2c, 02-097 02-097 Warsaw, Warsaw, Poland; [email protected]@cent.uw.edu.pl (M.J.); (M.J.); [email protected] [email protected] (A.M.) (A.M.) 2 Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland 2 Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland * Correspondence: [email protected] * Correspondence: [email protected] Received: 28 28 June 2020; Accepted: 02 2 AugustAugust 2020;2020; Published:Published: 5date August 2020 Abstract: RutheniumRuthenium olefin olefin metathesis metathesis catalysts catalysts are are one one of of the most commonly used class of catalysts. There There are are multiple multiple reviews reviews on on their their us useses in in various branches of chemistry and other sciences but a detailed review of their decomposition is missing, despite a large number of recent and important advances advances in in this this field. field. In In particular, particular, in in the the last last five five years years several several new new mechanism mechanism of decomposition,of decomposition, both both olefin-driven olefin-driven as well as well as induc as induceded by external by external agents, agents, have have been been suggested suggested and usedand usedto explain to explain differences differences in the decomposition in the decomposition rates and rates the metathesis and the metathesis activities activitiesof both standard, of both N-heterocyclicstandard, N-heterocyclic carbene-based carbene-based systems and systems the recently and the developed recently developed cyclic alkyl cyclic amino alkyl carbene- amino containingcarbene-containing complexes.
    [Show full text]
  • Renewable Polymers from Itaconic Acid
    RENEWABLE POLYMERS FROM ITACONIC ACID A Dissertation Presented to the Faculty of the Graduate School of Cornell University In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Jacob Thomas Trotta August 2019 © 2019 Jacob Thomas Trotta ii RENEWABLE POLYMERS FROM ITACONIC ACID Jacob Thomas Trotta, Ph. D. Cornell University 2019 Itaconic acid (IA) is a biorenewable compound that is generated inexpensively and in large amounts by the fermentation of biomass. While a variety of structurally diverse polymers have been accessed from IA, continued exploration of efficient syntheses and polymerizations of novel monomers could lead to the development of sustainable materials that can help reduce society’s dependence of petroleum (Chapter 1). We show that from β-monomethyl itaconate, an IA derivative, we can utilize a selective addition strategy that allows access to both α-methylene-γ-butyrolactone (MBL, tulipalin A) and α-methylene-γ,γ-dimethyl-γ-butyrolactone (Me2MBL), which serve as high value biorenewable analogues to petroleum-derived methyl methacrylate. Subsequent polymerization of both Me2MBL and MBL through reversible addition- fragmentation chain-transfer (RAFT) polymerization generates well defined poly(Me2MBL) (PMe2MBL) and poly(MBL) (PMBL) polymers. Through physiochemical characterization, we show that PMe2MBL has desirable properties comparable with known PMBL materials (Chapter 2). We then extend our strategy to produce triblock polymers using PMBL end blocks with an IA-derived polyester mid- block. Using catalytic, solvent-free, and high yielding transformations from an itaconate source, we efficiently synthesize a saturated diol, a saturated diester, and an unsaturated diester. Subsequent step-growth polycondensation polymerizations of these monomers leads to polyesters with relatively high molar masses (> 10 kg/mol).
    [Show full text]
  • A Convenient Method for Removing All Highly-Colored Byproducts Generated During Olefin Metathesis Reactions
    ORGANIC LETTERS 2000 A Convenient Method for Removing All Vol. 2, No. 9 Highly-Colored Byproducts Generated 1259-1261 during Olefin Metathesis Reactions Leo A. Paquette,* Jeffrey D. Schloss, Ivan Efremov, Fabrizio Fabris, Fabrice Gallou, Jose´Me´ndez-Andino, and Jiong Yang EVans Chemical Laboratories, The Ohio State UniVersity, Columbus, Ohio 43210 [email protected] Received February 18, 2000 ABSTRACT Addition of a very modest amount of lead tetraacetate (1.50 equiv relative to the amount of Grubbs catalyst) to ring-closing metathesis reaction mixtures effectively removes all colored ruthenium and phosphine impurities to deliver colorless reaction products. The olefin metathesis reactions, in their cross-coupling, ring- employed, although its general ineffectiveness for producing opening, and particularly ring-closing modes,1,2 have devel- trisubstituted alkenes is generally recognized.7 oped into processes that are of considerable value to organic synthesis.3 The striking advances that have materialized in recent years stem largely from the availability of efficient molybdenum4 and ruthenium5 precatalysts having well- balanced electronic and coordinative unsaturation such that high turnover performance is manifested. Due to its increased stability, the Grubbs catalyst 16 has been most widely (1) Olefin Metathesis and Metathesis Polymerization; Ivin, K. J., Mol, J. C., Academic Press: New York, 1997. Despite the major advantages offered by this group of (2) Alkene Metathesis in Organic Synthesis;Fu¨rstner, A., Ed.; Springer: reactions, they share the same complication. Removal of the Berlin, 1998. (3) For recent reviews, consult: (a) Grubbs, R. H.; Miller, S. J.; Fu, G. darkly colored, metal-containing byproducts upon completion C.
    [Show full text]