DOCSLIB.ORG

The Suzuki–Miyaura Reaction As a Tool for Modification of Phenoxyl

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Suzuki–Miyaura Reaction As a Tool for Modification of Phenoxyl RSC Advances PAPER View Article Online View Journal | View Issue The Suzuki–Miyaura reaction as a tool for modification of phenoxyl-nitroxyl radicals of the Cite this: RSC Adv.,2018,8,26099 4H-imidazole N-oxide series† Yury A. Ten, a Oleg G. Salnikov,b Svetlana A. Amitina, a Dmitri V. Stass,bc Tatyana V. Rybalova, ab Maxim S. Kazantsev, ab Artem S. Bogomyakov, d Evgeny A. Mostovich ab and Dmitrii G. Mazhukin *ab 2-(3,5-Di-tert-butyl-4-hydroxyphenyl)-5-(4-iodophenyl)-4,4-dimethyl-4H-imidazole 3-oxide reacts with phenylboronic acid and its substituted derivatives in a cross-coupling reaction of the Suzuki–Miyaura type to form 5-biphenyl derivatives of 4H-imidazole-N-oxide. Interaction of the same compound with B2(pin)2 in the presence of PdCl2(PPh3)2 proceeds through the formation of intermediate 1,3,2- dioxoborolane and leads to the product of homocoupling: biphenyl-bis(imidazole). Oxidation of the resultant imidazoles with lead dioxide quantitatively yields stable conjugated phenoxyl-nitroxyl mono- Received 13th June 2018 Creative Commons Attribution-NonCommercial 3.0 Unported Licence. and diradicals, which are of interest as electroactive paramagnetic materials. The crystal structure of the Accepted 13th July 2018 monoradical, 2,6-di-tert-butyl-4-[1-oxido-4-(biphenyl-4-yl)-5,5-dimethyl-1H-imidazole-2(5H)-ylidene] DOI: 10.1039/c8ra05103h cyclohex-2,5-dienone, its magnetic susceptibility, EPR spectra of the obtained hybrid radicals in solution, rsc.li/rsc-advances and cyclic voltammetry characteristics of 4H-imidazoles were studied. Introduction oxide series (Chart 1),9 we turned our attention to the possibility of modifying the para-haloaryl group at the 5th position of the The cross-coupling reaction of the Suzuki–Miyaura type1 can be heterocycle using Pd-catalyzed cross-coupling reactions, in This article is licensed under a undoubtedly considered as one of the fundamental methods for particular, the Suzuki–Miyaura process. constructing aromatic and heteroaromatic ensembles in the On the one hand, the introduction of an electron- synthesis of biologically active compounds for pharmaceutical withdrawing type of substituent possessing an ÀM-effect into 2 Open Access Article. Published on 20 July 2018. Downloaded 10/1/2021 11:45:19 PM. chemistry as well as in the chemistry of new materials (prep- the para-position of the 5-aryl moiety should lead to the addi- aration of components of optoelectronic devices3 and liquid- tional stabilization of the radical center owing to further crystalline semiconducting oligomers4) and in organic photo- distribution of the electron density of an unpaired electron over voltaics.5 Recent research on the Suzuki–Miyaura reaction the conjugated system. On the other hand, further functional- includes extensive studies of various substrates involved in this ization of hybrid radicals means developing their practical process (for example, low-reactive aryl chlorides, aryl uorides, or tosylates),6 a wide range of reagents (boronic acids and their derivatives),7 and several generations of palladium catalysts with different ligand environments.8 Continuing the research on the reactivity of new stable radicals, i.e., hybrid phenoxyl-nitroxides of the 4H-imidazole N- aNN Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, 9 Acad. Lavrentyeva Ave., Novosibirsk, 630090, Russia, [email protected] bNovosibirsk State University, 2 Pirogova Str., Novosibirsk, 630090, Russia cVoevodsky Institute of Chemical Kinetics and Combustion SB RAS, 3 Institutskaya Str., Novosibirsk, 630090, Russia dInternational Tomography Center SB RAS, 3A Institutskaya Str., Novosibirsk, 630090, Russia † Electronic supplementary information (ESI) available: Synthetic procedures, analytical and spectroscopic data for all new compounds. Experimental and simulated ESR spectra for the new radicals, CV data for 4H-imidazole N-oxides. Chart 1 Examples of stable hybrid radicals: 4H-imidazole N-oxide CCDC 1564701. For ESI and crystallographic data in CIF or other electronic based phenoxyl-nitroxides (PN); 1,2,3-dithiazolo-1,2,4-thiadiazinyls format see DOI: 10.1039/c8ra05103h (DTA-TDA). This journal is © The Royal Society of Chemistry 2018 RSC Adv.,2018,8, 26099–26107 | 26099 View Article Online RSC Advances Paper applicability because of creation of new promising dyadic and radical with a mild selective reagent whose redox potential triadic molecular systems. cannot change the paramagnetic status of the substrate. In this While developing fundamentally new smart devices based respect, a study on Pd-catalyzed C–C cross-coupling reactions on fully organic materials, researchers have become more (particularly, the Suzuki–Miyaura process) involving various interested in the design and construction of dyads and triads of types of persistent radicals was carried out here under the DA (donor–acceptor) or ADA (acceptor–donor–acceptor) types, conditions of both methods. where the group containing a stable radical moiety plays the For example, thermally unstable nitroxyl radicals stabilized role of the acceptor.10 These systems can be considered molec- by nitroxyl group conjugation with the benzene nucleus (t- ular switches (transforming from a neutral state to a zwitter- butylaryl, tetrahydroquinolinyl, [3,1]-benzoxazinyl, and dihy- ionic or diradical form in solution under the inuence of droacridinyl type) were introduced into the Suzuki–Miyaura external stimuli, i.e., temperature, pressure, or light), and some reaction in the form of their stable precursors, namely, of them can have properties of conductors in a solid form.11 secondary amines. Aer formation of the cross-coupling prod- Typical examples of such dyads and triads are shown in Chart 2. ucts, the latter were transformed into target nitroxides with m- As for stable hybrid radicals, only a few representatives of CPBA in a yield of 37–70%.13 At the same time, more robust this type of paramagnetics were synthesized by scientists in the iodoarene derivatives of the benzotriazinyl radical (Blatter's last decade. For instance, resonance-stabilized planar 1,2,3- radical),14a–c verdazyl radical,14d and iso-indolinoxyls14e readily dithiazolo-1,2,4-thiadiazinyl12a (Chart 1) and related radicals12b reacted in cross-coupling with either arylboronic acids or aryl- possess highly delocalized and easily tuned spin distributions. triolborate salts, which in contrast to parent acids possess Therefore, the wide range of physical and chemical properties greater reactivity. Depending on the number of iodoarene of thiazyl-based radicals make them useful building blocks for groups in these radicals, mono-, bis-, and tris-cross-coupling magnetic and conductive materials as well as coordinating products were obtained without losing a radical center. The ligands. yields ranged from 97% for the mono-cross-coupling product to Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Depending on the kinetic stability of radical types, there are 67% for bis- and 52% for the tris-phenyl-substituted compound. two fundamentally different methods for their functionaliza- As to the cyclic nitroxide based on an imidazole nucleus, to the tion. The rst method represents the interaction of their best of our knowledge, there is only one report about the diamagnetic precursors directly along a reactive group with Suzuki–Miyaura reaction involving nitronyl nitroxyl radicals various nucleophilic or electrophilic reagents, and the radical containing an ortho(meta)-iodophenyl group at the C-2 atom of center is generated at the nal stage, when the product is the heterocycle. The authors explained a rather low yield of treated with an oxidizing agent (or an excess of an electrophilic cross-coupling products in this reaction (40–43% for the ortho- reagent). The second method consists of treating the stable iodophenyl derivative and 44% for the meta-iodophenyl deriv- ative) by competitive destruction of a nitronyl nitroxide occur- This article is licensed under a ring at the elevated temperature under typical conditions of the Suzuki process (80 C, 2 h).15 Accordingly, it was interesting to nd out how hybrid Open Access Article. Published on 20 July 2018. Downloaded 10/1/2021 11:45:19 PM. phenoxyl-nitroxide radicals would behave under the conditions of the Suzuki–Miyaura reaction and whether they would be sufficiently stable to retain the paramagnetic center. Besides, Pd-catalyzed cross-coupling reactions involving 5-(haloaryl)-4H- imidazole derivatives and their N-oxides are not mentioned in any databases. Results and discussion To conduct cross-coupling experiments, the para-iodoarene substituted derivative of 4H-imidazole N-oxide was chosen as a model substrate because solely iodo derivatives show the greatest reactivity among other haloaryl compounds and produce quantitative yields of biphenyls under the classical Suzuki reaction conditions. A diamagnetic precursor of the hybrid radical, key 5-(p- iodophenyl)substituted 4H-imidazole 3-oxide 1, was synthe- sized in 6 stages based on Friedel–Cras acylation of an iodo- benzene excess with iso-butyric acid chloride followed by bromination of 4-iodo-iso-butyrophenone 2, treatment of Chart 2 Some electroactive and photoactive dyads and triads based bromo compound 3 with hydroxylamine, and hydrolysis of the on stable radicals: oxophenalyloxyl (A),10i phenoxyl-imidazolyl (B),10d,f formed 2-hydroxylamine oxime 4 by boiling with concentrated di-tert-butyl-ortho-semiquinonyl (C),10e,g and trityl (D).10b hydrobromic acid. Condensation of the obtained salt of 2- 26100 | RSC
Load more

Recommended publications
  • Pd/C-Catalyzed Suzuki Cross- and Self- Couplings &
    PD/C-CATALYZED SUZUKI CROSS- AND SELF- COUPLINGS & THE DEVELOPMENT OF A LAB-SCALE HYDROGENATION SYSTEM by JENG-SHIOU CHEN A Dissertation submitted to the Graduate School-New Brunswick Rutgers, The State University of New Jersey In partial fulfillment of the requirements For the degree of Doctor of Philosophy Graduate Program in Chemical and Biochemical Engineering Written under the direction of Professor Johannes G. Khinast And approved by ________________________ ________________________ ________________________ ________________________ New Brunswick, New Jersey Jan. 2008 ABSTRACT OF THE DISSERTATION PD/C-CATALYZED SUZUKI CROSS- AND SELF- COUPLINGS & THE DEVELOPMENT OF A LAB-SCALE HYDROGENATION SYSTEM By JENG-SHIOU CHEN Dissertation Directors: Professor Johannes G. Khinast Suzuki couplings have become an efficient and clean strategy for the preparation of biologically active functionalized biphenyls, which are important building blocks for pharmaceutical and agricultural compounds. Among all catalysts of choice for Suzuki couplings, palladium on carbon (Pd/C) is most frequently used for industrial applications due to its high catalytic activity, low cost and easy removal from the reaction mixture. Using a model coupling reaction of biphenylacetic acid, we intended to provide a thorough understanding of Pd/C-catalyzed Suzuki couplings for a straightforward industrial implementation. A detailed investigation of the reaction parameters was carried out in Chapter 2. The experimental observations indicate that excess amount of the borate is helpful to accelerate the reaction and 2 moles eq. of a strong base is the best choice for the reaction. Furthermore, our results suggest that transmetalation is the rate-limiting step of the Pd/C-catalyzed Suzuki couplings and also show that [OH-] is a critical factor affecting the reaction rate.
    [Show full text]
  • 2D Porous Polymers with Sp2-Carbon Connections
    2D Porous Polymers with sp2-Carbon Connections and Sole sp2-Carbon Skeletons Jialing Kang, Senhe Huang, Kaiyue Jiang, Chenbao Lu, Zhenying Chen, Jinhui Zhu, Chongqing Yang, Artur Ciesielski, Feng Qiu, Xiaodong Zhuang To cite this version: Jialing Kang, Senhe Huang, Kaiyue Jiang, Chenbao Lu, Zhenying Chen, et al.. 2D Porous Polymers with sp2-Carbon Connections and Sole sp2-Carbon Skeletons. Advanced Functional Materials, Wiley, 2020, 30 (27), pp.2000857. 10.1002/adfm.202000857. hal-03117175 HAL Id: hal-03117175 https://hal.archives-ouvertes.fr/hal-03117175 Submitted on 20 Jan 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Two-Dimensional Porous Polymers with sp2-Carbon Connections and Sole sp2-Carbon Skeletons Jialing Kang, Senhe Huang, Kaiyue Jiang, Chenbao Lu, Zhenying Chen, Jinhui Zhu, Chongqing Yang,* Artur Ciesielski, Feng Qiu,* and Xiaodong Zhuang* J. Kang, S. Huang, K. Jiang, C. Lu, Z. Chen, Dr. J. Zhu, Dr. C. Yang, Prof. X. Zhuang The Meso-Entropy Matter Lab, SChool of Chemistry and ChemiCal Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China E-mail: [email protected], [email protected] J. Kang, Prof.
    [Show full text]
  • Desperately Seeking for the Catalytic Species in Suzuki-Miyaura Reaction Amine Bourouina
    Desperately Seeking For The Catalytic Species In Suzuki-Miyaura Reaction Amine Bourouina To cite this version: Amine Bourouina. Desperately Seeking For The Catalytic Species In Suzuki-Miyaura Reaction. Chemical and Process Engineering. Université de Lyon, 2019. English. NNT : 2019LYSE1258. tel-02482607 HAL Id: tel-02482607 https://tel.archives-ouvertes.fr/tel-02482607 Submitted on 18 Feb 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. N°d’ordre NNT : 2019LYSE1258 THESE de DOCTORAT DE L’UNIVERSITE DE LYON opérée au sein de l’Université Claude Bernard Lyon 1 Ecole Doctorale ED206 Ecole Doctorale de Chimie de Lyon Spécialité de doctorat : Discipline : Procédés Soutenue publiquement le 28/11/2019, par : Amine BOUROUINA Desperately Seeking For The Catalytic Species In Suzuki-Miyaura Reaction Devant le jury composé de : FERRIGNO Rosaria, Professeure des Universités, Université Lyon Présidente HII King Kuok (Mimi), Professeure, L'Imperial College de Londres Rapporteuse RIANT Olivier, Professeur ordinaire, Université Catholique de Louvain Rapporteur
    [Show full text]
  • Stille and Suzuki-Miyaura Reactions
    molecules Article Recoverable Palladium-Catalyzed Carbon-Carbon Bond Forming Reactions under Thermomorphic Mode: Stille and Suzuki-Miyaura Reactions Eskedar Tessema 1,†, Vijayanath Elakkat 1,† , Chiao-Fan Chiu 2,3,*, Zong-Lin Tsai 1, Ka Long Chan 1 , Chia-Rui Shen 4,5, Han-Chang Su 6 and Norman Lu 1,7,* 1 Institute of Organic and Polymeric Materials, National Taipei University of Technology, Taipei 106, Taiwan; [email protected] (E.T.); [email protected] (V.E.); [email protected] (Z.-L.T.); [email protected] (K.L.C.) 2 Department of Pediatrics, Linkou Medical Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan 3 Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan 4 Department of Medical Biotechnology and Laboratory Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; [email protected] 5 Department of Ophthalmology, Linkou Medical Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan 6 Creditable Service Technology Consultants, New Taipei City 235, Taiwan; [email protected] 7 Development Center for Smart Textile, National Taipei University of Technology, Taipei 106, Taiwan * Correspondence: [email protected] (C.-F.C.); [email protected] (N.L.). † These authors contributed equally to this work. Citation: Tessema, E.; Elakkat, V.; 0 0 Chiu, C.-F.; Tsai, Z.-L.; Chan, K.L.; Abstract: The reaction of [PdCl2(CH3CN)2] and bis-4,4 -(RfCH2OCH2)-2,2 -bpy (1a–d), where Rf = n- Shen, C.-R.; Su, H.-C.; Lu, N. C11F23 (a), n-C10F21 (b), n-C9F19 (c) and n-C8F17 (d), respectively, in the presence of dichloromethane 0 0 Recoverable Palladium-Catalyzed (CH2Cl2) resulted in the synthesis of Pd complex, [PdCl2[4,4 -bis-(RfCH2OCH2)-2,2 -bpy] (2a–d).
    [Show full text]
  • The Nobel Prize in Chemistry 2010 the Royal Swedish Academy of Sciences Has Decided to Award the Nobel Prize in Chemistry for 2010 To
    PRESSMEDDELANDE Press release 6 October 2010 The Nobel Prize in Chemistry 2010 The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Chemistry for 2010 to Richard F. Heck Ei-ichi Negishi and Akira Suzuki University of Delaware, Newark, DE, USA, Purdue University, West Lafayette, Hokkaido University, Sapporo, IN, USA Japan “for palladium-catalyzed cross couplings in organic synthesis”. Great art in a test tube Organic chemistry has developed into an art form hods worked when creating simple molecules, but when where scientists produce marvelous chemical crea- synthesizing more complex molecules chemists ended up tions in their test tubes. Mankind benefits from this in with too many unwanted by-products in their test tubes. the form of medicines, ever-more precise electronics Palladium-catalyzed cross coupling solved that problem and advanced technological materials. The Nobel and provided chemists with a more precise and efficient Prize in Chemistry 2010 awards one of the most tool to work with. In the Heck reaction, Negishi reaction sophisticated tools available to chemists today. and Suzuki reaction, carbon atoms meet on a palladium atom, whereupon their proximity to one another kick- This year’s Nobel Prize in Chemistry is awarded to starts the chemical reaction. Richard F. Heck, Ei-ichi Negishi and Akira Suzuki for the development of palladium-catalyzed cross coupling. This Palladium-catalyzed cross coupling is used in research chemical tool has vastly improved the possibilities for worldwide, as well as in the commercial production of chemists to create sophisticated chemicals, for example for example pharmaceuticals and molecules used in the carbon-based molecules as complex as those created by electronics industry.
    [Show full text]
  • Noc19 Cy15 Assignment3
    Metal Mediated Synthesis I - - Unit 3 - Week 2 https://onlinecourses.nptel.ac.in/noc19_cy15/uni... X [email protected] ▼ Courses » Metal Mediated Synthesis I Announcements Course Ask a Question Progress FAQ Unit 3 - Week 2 Register for Certification exam Assignment_2_Week-2_Met Med Synth-I The due date for submitting this assignment has passed. Course As per our records you have not submitted this Due on 2019-02-13, 23:59 IST. outline assignment. How to access 1) Name of the following coupling reaction is 1 point the portal? Week 1 Week 2 Lecture 6 :Catalytic Cyclopropanation Kumada coupling reaction Reaction & Introduction to Stille Coupling reaction Cross Coupling Reaction Suzuki coupling reaction Lecture 7 None of the above :Kumada No, the answer is incorrect. Coupling Reaction Score: 0 Accepted Answers: Lecture 8 :Suzuki Suzuki coupling reaction Coupling Reaction 2) In Stille coupling reaction the order of transmetalation for aryl is more than 1 point alkyl;- state whether the statement is true or false. Lecture 9 :Stille Coupling True Reaction False Lecture 10 :Assymetric No, the answer is incorrect. Suzuki Score: 0 Coupling Reaction Accepted Answers: True Download Videos 3) The reactivity pattern of aryl halides in the coupling reactions is usually follow 1 point Weekly - Feedback Cl>Br>I Quiz : © 2014 NPTEL - Privacy & Terms - Honor Code - FAQs - A projectAssignment_2_Week-2_Met of Br > I > Cl In association with Med Synth-I I > Cl > Br Assignment 2 Solutions I > Br > Cl Funded by New Lesson No, the answer is incorrect. 1 of 4 Thursday 02 May 2019 04:41 PM Metal Mediated Synthesis I - - Unit 3 - Week 2 https://onlinecourses.nptel.ac.in/noc19_cy15/uni..
    [Show full text]
  • Regioselective Suzuki Couplings of Non -Symmetric Dibromobenzenes: Alkenes As Regiochemical Control Elements
    Organic & Biomolecular Chemistry Regioselective Suzuki Couplings of Non -Symmetric Dibromobenzenes: Alkenes as Regiochemical Control Elements Journal: Organic & Biomolecular Chemistry Manuscript ID: OB-COM-04-2015-000717 Article Type: Communication Date Submitted by the Author: 10-Apr-2015 Complete List of Authors: Zhao, Peng; Oregon State University, Chemistry Young, Marshall; Oregon State University, Chemistry Beaudry, Chris; Oregon State University, Chemistry Page 1 of 4 Organic & Biomolecular Chemistry Journal Name RSC Publishing COMMUNICATION Regioselective Suzuki Couplings of Non-Symmetric Dibromobenzenes: Alkenes as Regiochemical Control Cite this: DOI: 10.1039/x0xx00000x Elements * Received 00th January 2012, Peng Zhao, Marshall D. Young and Christopher M. Beaudry Accepted 00th January 2012 DOI: 10.1039/x0xx00000x www.rsc.org/ The regiochemical outcome of Suzuki couplings of non- symmetric dibromobenzenes is investigated. Selectivities are dependent on the proximity of the bromine atom to alkene substituents, not on steric or electronic effects. Extension to a one-pot three-component Suzuki reaction leads to efficient terphenyl syntheses. The Suzuki cross-coupling has emerged as a mainstay of organic synthesis, and it is especially useful for the construction of Csp 2–Csp 2 bonds. The traditional application of the Suzuki reaction is the coupling of a halide with a boron reagent (Scheme 1, eq. 1). 1 Substantial efforts have expanded the Suzuki reaction, and they include many examples of chemoselective couplings that exploit the reactivity differences of the halogens (eq. 2) 2. In addition to benzene systems, such chemoselective Suzuki reactions are also known in polycyclic aromatic molecules such as quinolines3, napthalenes 4, and indoles.5 Additionally there are many examples of tandem couplings of polyhalides (eq.
    [Show full text]
  • Palladium-Catalyzed Suzuki–Miyaura Cross-Coupling in Continuous Flow
    catalysts Review Palladium-Catalyzed Suzuki–Miyaura Cross-Coupling in Continuous Flow Christophe Len 1,*, Sophie Bruniaux 1, Frederic Delbecq 2 and Virinder S. Parmar 3 1 Centre de Recherche Royallieu, Université de Technologie de Compiègne (UTC), Sorbonne Universités, CS 60319, F-60203 Compiègne CEDEX, France; [email protected] 2 Ecole Supérieure de Chimie Organique et Minérale (ESCOM), 1 rue du Réseau Jean-Marie Buckmaster, F-60200 Compiègne, France; [email protected] 3 Institute of Advanced Sciences, 86-410 Faunce Corner Mall Road, Dartmouth, MA 02747, USA; [email protected] * Correspondence: [email protected]; Tel.: +33-344-234-323 Academic Editor: Ioannis D. Kostas Received: 15 March 2017; Accepted: 25 April 2017; Published: 9 May 2017 Abstract: Carbon–carbon cross-coupling reactions are among the most important processes in organic chemistry and Suzuki–Miyaura reactions are the most widely used protocols. For a decade, green chemistry and particularly catalysis and continuous flow, have shown immense potential in achieving the goals of “greener synthesis”. To date, it seems difficult to conceive the chemistry of the 21st century without the industrialization of continuous flow process in the area of pharmaceuticals, drugs, agrochemicals, polymers, etc. A large variety of palladium Suzuki–Miyaura cross-coupling reactions have been developed using a continuous flow sequence for preparing the desired biaryl derivatives. Our objective is to focus this review on the continuous flow Suzuki–Miyaura cross-coupling using homogeneous and heterogeneous catalysts. Keywords: palladium; continuous flow; Suzuki–Miyaura; cross-coupling 1. Introduction Among the main reactions in organic chemistry, C–C bond formation via a cross-coupling reaction catalyzed by transition metals is undoubtedly the most important and has been exploited very widely in the recent years.
    [Show full text]
  • Palladium Nanoparticles Tethered in Amine-Functionalized Hypercrosslinked Organic Tubes As an Efficient Catalyst for Suzuki Coupling in Water
    catalysts Article Palladium Nanoparticles Tethered in Amine-Functionalized Hypercrosslinked Organic Tubes as an Efficient Catalyst for Suzuki Coupling in Water Arindam Modak 1,2, Jing Sun 1, Wenjun Qiu 1 and Xiao Liu 1,* 1 Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; [email protected] (A.M.); [email protected] (J.S.); [email protected] (W.Q.) 2 Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700032, India * Correspondence: [email protected]; Tel./Fax: +86-22-2789-0859 Academic Editor: Ioannis D. Kostas Received: 7 September 2016; Accepted: 14 October 2016; Published: 20 October 2016 Abstract: It is highly desirable to design functionalized supports in heterogeneous catalysis regarding the stabilization of active sites. Pd immobilization in porous polymers and henceforth its application is a rapidly growing field. In virtue of its’ scalable synthesis and high stability in reaction conditions, amorphous polymers are considered an excellent scaffold for metal mediated catalysis, but the majority of them are found as either agglomerated particles or composed of rough spheres. Owing to several important applications of hollow organic tubes in diverse research areas, we aimed to utilize them as support for the immobilization of Pd nanoparticles. Pd immobilization in nanoporous polymer tubes shows high activity in Suzuki cross coupling reactions between aryl halides and sodium phenyl trihydroxyborate in water, which deserves environmental merit. Keywords: porous organic tubes; heterogeneous catalysis; Suzuki coupling in water 1. Introduction Porous organic polymers (POPs) are emerging as next-generation support materials for heterogeneous catalysis [1–6].
    [Show full text]
  • Morphological Aspects
    Molecules 2015, 20, 18661-18684; doi:10.3390/molecules201018661 OPEN ACCESS molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Article Resin-Immobilized Palladium Nanoparticle Catalysts for Organic Reactions in Aqueous Media: Morphological Aspects Piero Mastrorilli 1,*, Maria M. Dell’Anna 1, Antonino Rizzuti 1, Matilda Mali 1, Mauro Zapparoli 2 and Cristina Leonelli 3 1 Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e di Chimica (DICATECh), Politecnico di Bari, via Orabona 4, Bari 70125, Italy; E-Mails: [email protected] (M.M.D.A.); [email protected] (A.R.); [email protected] (M.M.) 2 Centro Interdipartimentale Grandi Strumenti (C.I.G.S.), Università di Modena e Reggio Emilia, via Campi 213\A, Modena 41125, Italy; E-Mail: [email protected] 3 Dipartimento di Ingegneria “Enzo Ferrari”, Università di Modena e Reggio Emilia, via Pietro Vivarelli 10, Modena 41125, Italy; E-Mail: [email protected] * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +39-80-596-3605; Fax: +39-80-596-3611. Academic Editors: Nicola Cioffi, Antonio Monopoli and Massimo Innocenti Received: 24 September 2015 / Accepted: 8 October 2015 / Published: 14 October 2015 Abstract: An insight into the nano- and micro-structural morphology of a polymer supported Pd catalyst employed in different catalytic reactions under green conditions is reported. The pre-catalyst was obtained by copolymerization of the metal-containing monomer − Pd(AAEMA)2 [AAEMA = deprotonated form of 2-(acetoacetoxy) ethyl methacrylate] with ethyl methacrylate as co-monomer, and ethylene glycol dimethacrylate as cross-linker. This material was used in water for the Suzuki-Miyaura cross-coupling of aryl bromides, and for the reduction of nitroarenes and quinolines using NaBH4 or H2, as reductants.
    [Show full text]
  • Conjugated Porous Polymers for Heterogeneous Visible Light Photocatalysis
    Conjugated Porous Polymers for Heterogeneous Visible Light Photocatalysis Dissertation Zur Erlangung des Grades „Doktor der Naturwissenschaften“ im Promotionsfach Chemie dem Fachbereich Chemie, Pharmazie und Geowissenschaften der Johannes Gutenberg-Universität Mainz. Zi Jun Wang Geboren in Yuncheng, China Mainz, December 2015 1 2 Dekan: 1. Gutachter: 2. Gutachter: Tag der mündlichen Prüfung: 3 Affidavit I hereby confirm that I have completed the present dissertation independently and without inadmissible external support. I have not used any sources or tools other than those indicated and have identified literal and analogous quotations. Furthermore, I confirm that this thesis has not yet been submitted as part of another examination process neither in identical nor in similar form. Place, date: Signature: i Zusammenfassung Konjugierte poröse Polymere (CPP) verbinden in idealer Weise die Eigenschaften eines photoaktiven Polymergrundgerüstes mit reichem Gehalt an π-Elektronen mit einer porösen spezifischen Oberfläche. Daher sind diese Materialien auf großes Interesse in der Wissenschaft gestoßen. Tatsächlich werden CPPs für eine Reihe von traditionalen Anwendungen wie Gasadsorption, Filtration, Katalyse und Lichtkonversion angewendet. In dieser Dissertation wurde eine neue Anwendungsmöglichkeit der CPPs auf ihrer hervorragenden Lichtadsorptionseigenschaft und hoher Porosität hervorgehend, nämlich die metallfreie heterogene Photokatalyse unter Bestrahlung mit sichtbarem Licht, dargestellt. Wichtige Aspekte wie Porosität, Morphologie, Bandstrukturen,
    [Show full text]
  • A Powerful Tool for Chemists
    THE NOBEL PRIZE IN CHEMISTRY 2010 INFORMATION FOR THE PUBLIC A Powerful Tool for Chemists There is an increasing need for complex chemicals. Humanity wants new medicines that can cure cancer or halt the devastating effects of deadly viruses in the human body. The electronics industry is searching for substances that can emit light, and the agricultural industry wants substances that can protect crops. The Nobel Prize in Chemistry 2010 rewards a tool that has improved the ability of chemists to satisfy all of these wishes very effciently: palladium-catalyzed cross coupling. At the end of the 1980s, scuba divers in the Caribbean Sea collected the marine sponge Discodermia dis- soluta. At a depth of 33 meters (108 feet) they found a little creature that lacks eyes, a mouth, stomach and bones. At frst sight it appears primitive, but its inability to escape enemies has turned Discodermia dissoluta and other marine sponges into masters of chemistry. They have a remarkable ability to produce large and complex chemical molecules that are poisonous and that prevent other organisms from exploiting them. Researchers have discovered that many of these poisons have therapeutic properties; they can function as antibiotics or as anti-viral or anti-infammatory medicines. In the case of Discodermia dissoluta, the frst laboratory tests revealed that the substance discodermolide could in the future be used as a chemotherapy drug. Among other things, it stopped cancer cells from growing in test tubes. Removes a significant obstacle to progress After more in-depth studies, scientists have been able to demonstrate how discodermolide defeats cancer cells in the same manner as Taxol, one of the most commonly used cancer drugs in the world.
    [Show full text]