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Nakano Y, Maddigan-Wyatt JT, Lupton DW. Enantioselective Catalysis by the Umpolung of Conjugate Acceptors Involving N-Heterocyclic Carbene or Organophosphine 1,4-Addition. Acc Chem Res 2023; 56:1190-1203. [PMID: 37093247 DOI: 10.1021/acs.accounts.3c00063] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
ConspectusConjugate acceptors are one of the most common electrophilic functional groups in organic synthesis. While useful in a diverse range of transformations, their applications are largely dominated by the reactions from which their name is derived (i.e., as an acceptor of nucleophiles in the conjugate position). In 2014, we commenced studies focused on their ability to undergo polarity inversion through the conjugate addition of Lewis base catalysts. The first step in this process provides an enolate, from which the well-developed Rauhut-Currier (RC) and Morita-Baylis-Hillman (MBH) reactions can occur; however, tautomerization to provide a species in which the β-carbon of the conjugate acceptor can now act as a donor is also possible. When we commenced studies on this topic, reaction designs with this type of species, particularly when accessed using N-heterocyclic carbenes (NHCs), had been reported on only a handful of occasions. Despite a lack of development, conceptually it was felt that reactions taking advantage of polarity switching by Lewis base conjugate addition have a number of desirable features. Perhaps the most significant is the potential to reimagine a ubiquitous functional group as an entirely new synthon, namely, a donor to electrophiles from the conjugate position.Our work has focused on catalysis with both simple conjugate acceptors and also those embedded within more complicated substrates; the latter has allowed a series of cycloisomerizations and annulation reactions to be achieved. In most cases, the reactions have been possible using enantioenriched chiral NHCs or organophosphines as the Lewis base catalysts thereby delivering enantioselective approaches to novel cyclic molecules. While related chemistry can be accessed with either family of catalyst, in all cases reactions have been designed to take advantage of one or the other. In addition, a fine balance exists between reactions that exploit the initially formed enolate and those that involve the polarity-inverted β-anion. In our studies, this balance is addressed through substrate design, although catalyst control may also be possible. We consider the chemistry discussed in this Account to be in its infancy. Significant challenges remain to be addressed before our broad aim of discovering a universal approach to the polarity inversion of all conjugate acceptors can be achieved. These challenges broadly relate to chemoselectivity with substrates bearing multiple electrophilic functionalities, reliance upon the use of conjugate acceptors, and catalyst efficiency. To address these challenges, advances in catalyst design and catalyst cooperativity are likely required.
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Affiliation(s)
- Yuji Nakano
- School of Chemistry, Monash University, Clayton 3800, Victoria, Australia
| | | | - David W Lupton
- School of Chemistry, Monash University, Clayton 3800, Victoria, Australia
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2
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Wu T, Tatton MR, Greaney MF. NHC Catalysis for Umpolung Pyridinium Alkylation via Deoxy‐Breslow Intermediates. Angew Chem Int Ed Engl 2022; 61:e202117524. [PMID: 35103381 PMCID: PMC9306516 DOI: 10.1002/anie.202117524] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Indexed: 12/24/2022]
Abstract
Umpolung N‐heterocyclic carbene (NHC) catalysis of non‐aldehyde substrates offers new pathways for C−C bond formation, but has proven challenging to develop in terms of viable substrate classes. Here, we demonstrate that pyridinium ions can undergo NHC addition and subsequent intramolecular C−C bond formation through a deoxy‐Breslow intermediate. The alkylation demonstrates, for the first time, that deoxy‐Breslow intermediates are viable for catalytic umpolung of areniums.
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Affiliation(s)
- Terence Wu
- School of Chemistry The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Matthew R. Tatton
- Early Chemical Development Pharmaceutical Sciences R&D, AstraZeneca Macclesfield SK10 2NA UK
| | - Michael F. Greaney
- School of Chemistry The University of Manchester Oxford Road Manchester M13 9PL UK
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3
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Wu T, Tatton MR, Greaney MF. NHC Catalysis for Umpolung Pyridinium Alkylation via Deoxy-Breslow Intermediates. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 134:e202117524. [PMID: 38504766 PMCID: PMC10947523 DOI: 10.1002/ange.202117524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Indexed: 11/09/2022]
Abstract
Umpolung N-heterocyclic carbene (NHC) catalysis of non-aldehyde substrates offers new pathways for C-C bond formation, but has proven challenging to develop in terms of viable substrate classes. Here, we demonstrate that pyridinium ions can undergo NHC addition and subsequent intramolecular C-C bond formation through a deoxy-Breslow intermediate. The alkylation demonstrates, for the first time, that deoxy-Breslow intermediates are viable for catalytic umpolung of areniums.
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Affiliation(s)
- Terence Wu
- School of ChemistryThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - Matthew R. Tatton
- Early Chemical DevelopmentPharmaceutical SciencesR&D, AstraZenecaMacclesfieldSK10 2NAUK
| | - Michael F. Greaney
- School of ChemistryThe University of ManchesterOxford RoadManchesterM13 9PLUK
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4
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Tran-Do ML, Eid N, Totée C, Gimello O, Améduri B. Does the oxa-Michael reaction of 2-trifluoromethacrylic acid lead to fluorinated polyesters? Polym Chem 2021. [DOI: 10.1039/d1py00685a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
2-Trifluoromethacrylic acid (MAF) is a peculiar fluorinated functional monomer.
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Affiliation(s)
| | - Nadim Eid
- Institut Charles Gerhardt
- Univ. Montpellier
- CNRS
- ENSCM
- Montpellier
| | - Cédric Totée
- Institut Charles Gerhardt
- Univ. Montpellier
- CNRS
- ENSCM
- Montpellier
| | - Olinda Gimello
- Institut Charles Gerhardt
- Univ. Montpellier
- CNRS
- ENSCM
- Montpellier
| | - Bruno Améduri
- Institut Charles Gerhardt
- Univ. Montpellier
- CNRS
- ENSCM
- Montpellier
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5
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Xu T, Yu Z, Zhang X. Recyclable Vinyl‐Functionalized Polyesters via Chemoselective Organopolymerization of Bifunctional α‐Methylene‐δ‐Valerolactone. MACROMOL CHEM PHYS 2019. [DOI: 10.1002/macp.201900150] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Tie‐Qi Xu
- State Key Laboratory of Fine ChemicalsDepartment of ChemistrySchool of Chemical EngineeringDalian University of Technology Linggong Road No. 2 Dalian 116024 P. R. China
| | - Zhi‐Qi Yu
- State Key Laboratory of Fine ChemicalsDepartment of ChemistrySchool of Chemical EngineeringDalian University of Technology Linggong Road No. 2 Dalian 116024 P. R. China
| | - Xue‐Min Zhang
- State Key Laboratory of Fine ChemicalsDepartment of ChemistrySchool of Chemical EngineeringDalian University of Technology Linggong Road No. 2 Dalian 116024 P. R. China
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6
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Smith CA, Narouz MR, Lummis PA, Singh I, Nazemi A, Li CH, Crudden CM. N-Heterocyclic Carbenes in Materials Chemistry. Chem Rev 2019; 119:4986-5056. [PMID: 30938514 DOI: 10.1021/acs.chemrev.8b00514] [Citation(s) in RCA: 353] [Impact Index Per Article: 70.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
N-Heterocyclic carbenes (NHCs) have become one of the most widely studied class of ligands in molecular chemistry and have found applications in fields as varied as catalysis, the stabilization of reactive molecular fragments, and biochemistry. More recently, NHCs have found applications in materials chemistry and have allowed for the functionalization of surfaces, polymers, nanoparticles, and discrete, well-defined clusters. In this review, we provide an in-depth look at recent advances in the use of NHCs for the development of functional materials.
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Affiliation(s)
- Christene A Smith
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6
| | - Mina R Narouz
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6
| | - Paul A Lummis
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6
| | - Ishwar Singh
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6
| | - Ali Nazemi
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6
| | - Chien-Hung Li
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6
| | - Cathleen M Crudden
- Department of Chemistry , Queen's University , 90 Bader Lane , Kingston , Ontario , Canada , K7L 3N6.,Institute of Transformative Bio-Molecules, ITbM-WPI , Nagoya University , Nagoya , Chikusa 464-8601 , Japan
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7
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Schuster JK, Roy DK, Lenczyk C, Mies J, Braunschweig H. New Outcomes of Beryllium Chemistry: Lewis Base Adducts for Salt Elimination Reactions. Inorg Chem 2019; 58:2652-2658. [DOI: 10.1021/acs.inorgchem.8b03263] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Julia K. Schuster
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry and Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Dipak Kumar Roy
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry and Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Carsten Lenczyk
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry and Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jan Mies
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry and Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Holger Braunschweig
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- Institute for Sustainable Chemistry and Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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8
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Hong M, Chen J, Chen EYX. Polymerization of Polar Monomers Mediated by Main-Group Lewis Acid-Base Pairs. Chem Rev 2018; 118:10551-10616. [PMID: 30350583 DOI: 10.1021/acs.chemrev.8b00352] [Citation(s) in RCA: 170] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The development of new or more sustainable, active, efficient, controlled, and selective polymerization reactions or processes continues to be crucial for the synthesis of important polymers or materials with specific structures or functions. In this context, the newly emerged polymerization technique enabled by main-group Lewis pairs (LPs), termed as Lewis pair polymerization (LPP), exploits the synergy and cooperativity between the Lewis acid (LA) and Lewis base (LB) sites of LPs, which can be employed as frustrated Lewis pairs (FLPs), interacting LPs (ILPs), or classical Lewis adducts (CLAs), to effect cooperative monomer activation as well as chain initiation, propagation, termination, and transfer events. Through balancing the Lewis acidity, Lewis basicity, and steric effects of LPs, LPP has shown several unique advantages or intriguing opportunities compared to other polymerization techniques and demonstrated its broad polar monomer scope, high activity, control or livingness, and complete chemo- or regioselectivity, as well as its unique application in materials chemistry. These advances made in LPP are comprehensively reviewed, with the scope of monomers focusing on heteroatom-containing polar monomers, while the polymerizations mediated by main-group LAs and LBs separately that are most relevant to the LPP are also highlighted or updated. Examples of applying the principles of the LPP and LP chemistry as a new platform for advancing materials chemistry are highlighted, and currently unmet challenges in the field of the LPP, and thus the suggested corresponding future research directions, are also presented.
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Affiliation(s)
- Miao Hong
- State Key Laboratory of Organometallic Chemistry , Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , Shanghai 200032 , China
| | - Jiawei Chen
- Department of Chemistry , Columbia University , 3000 Broadway , New York , New York 10027 , United States
| | - Eugene Y-X Chen
- Department of Chemistry , Colorado State University , Fort Collins , Colorado 80523 , United States
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9
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Nesterov V, Reiter D, Bag P, Frisch P, Holzner R, Porzelt A, Inoue S. NHCs in Main Group Chemistry. Chem Rev 2018; 118:9678-9842. [PMID: 29969239 DOI: 10.1021/acs.chemrev.8b00079] [Citation(s) in RCA: 518] [Impact Index Per Article: 86.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Since the discovery of the first stable N-heterocyclic carbene (NHC) in the beginning of the 1990s, these divalent carbon species have become a common and available class of compounds, which have found numerous applications in academic and industrial research. Their important role as two-electron donor ligands, especially in transition metal chemistry and catalysis, is difficult to overestimate. In the past decade, there has been tremendous research attention given to the chemistry of low-coordinate main group element compounds. Significant progress has been achieved in stabilization and isolation of such species as Lewis acid/base adducts with highly tunable NHC ligands. This has allowed investigation of numerous novel types of compounds with unique electronic structures and opened new opportunities in the rational design of novel organic catalysts and materials. This Review gives a general overview of this research, basic synthetic approaches, key features of NHC-main group element adducts, and might be useful for the broad research community.
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Affiliation(s)
- Vitaly Nesterov
- Department of Chemistry, WACKER-Institute of Silicon Chemistry and Catalysis Research Center , Technische Universität München , Lichtenbergstrasse 4 , Garching bei München 85748 , Germany
| | - Dominik Reiter
- Department of Chemistry, WACKER-Institute of Silicon Chemistry and Catalysis Research Center , Technische Universität München , Lichtenbergstrasse 4 , Garching bei München 85748 , Germany
| | - Prasenjit Bag
- Department of Chemistry, WACKER-Institute of Silicon Chemistry and Catalysis Research Center , Technische Universität München , Lichtenbergstrasse 4 , Garching bei München 85748 , Germany
| | - Philipp Frisch
- Department of Chemistry, WACKER-Institute of Silicon Chemistry and Catalysis Research Center , Technische Universität München , Lichtenbergstrasse 4 , Garching bei München 85748 , Germany
| | - Richard Holzner
- Department of Chemistry, WACKER-Institute of Silicon Chemistry and Catalysis Research Center , Technische Universität München , Lichtenbergstrasse 4 , Garching bei München 85748 , Germany
| | - Amelie Porzelt
- Department of Chemistry, WACKER-Institute of Silicon Chemistry and Catalysis Research Center , Technische Universität München , Lichtenbergstrasse 4 , Garching bei München 85748 , Germany
| | - Shigeyoshi Inoue
- Department of Chemistry, WACKER-Institute of Silicon Chemistry and Catalysis Research Center , Technische Universität München , Lichtenbergstrasse 4 , Garching bei München 85748 , Germany
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10
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Ma S, Yu A, Meng X. Phosphine-catalyzed [4 + 2] annulation of γ-benzyl allenoates: facile synthesis of benzothieno[3,2-b]pyran derivatives. Org Biomol Chem 2018; 16:2885-2892. [DOI: 10.1039/c8ob00004b] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
An efficient tris(4-methoxyphenyl)phosphane catalyzed domino reaction between γ-benzyl allenoate and ethyl (Z)-2-(3-oxobenzo[b]thiophen-2(3H)-ylidene)acetate has been developed, which produces a series of 2H-benzo[4,5]thieno[3,2-b]pyran derivatives in high yields.
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Affiliation(s)
- Shanshan Ma
- Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion
- School of Chemistry & Chemical Engineering
- Tianjin University of Technology
- Tianjin 300384
- P. R. China
| | - Aimin Yu
- Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion
- School of Chemistry & Chemical Engineering
- Tianjin University of Technology
- Tianjin 300384
- P. R. China
| | - Xiangtai Meng
- Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion
- School of Chemistry & Chemical Engineering
- Tianjin University of Technology
- Tianjin 300384
- P. R. China
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11
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Yang J, Liu J, Wang Y, Wang J. Synthesis, structure and catalysis/applications of N-heterocyclic carbene based on macrocycles. J INCL PHENOM MACRO 2017. [DOI: 10.1007/s10847-017-0766-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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12
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Gowda RR, Chen EYX. Chemoselective Lewis pair polymerization of renewable multivinyl-functionalized γ-butyrolactones. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:20170003. [PMID: 28739962 PMCID: PMC5540837 DOI: 10.1098/rsta.2017.0003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/18/2017] [Indexed: 06/07/2023]
Abstract
Multivinyl-functionalized γ-butyrolactones, γ-vinyl-γ-methyl-α-methylene-γ-butyrolactone (γVMMBL) and γ-allyl-γ-methyl-α-methylene-γ-butyrolactone (γAMMBL), have been synthesized from biorenewable ethyl levulinate and effectively polymerized by Lewis pairs consisting of an organic N-heterocyclic carbene Lewis base and a strong organo-Lewis acid E(C6F5)3 (E = Al, B). This Lewis pair polymerization is quantitatively chemoselective, proceeds exclusively via polyaddition across the conjugated α-methylene double bond without participation of the γ-vinyl or γ-allyl double bond, and produces high-molecular-weight functionalized polymers with unimodal molecular-weight distributions. The Al-based Lewis pair produces a polymer with approximately 5.5 times higher molecular weight than that produced by the B-based Lewis pair. The resulting vinyl-functionalized polymers are soluble in common organic solvents and stable at room temperature, and can be thermally cured into crosslinked materials.This article is part of the themed issue 'Frustrated Lewis pair chemistry'.
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Affiliation(s)
- Ravikumar R Gowda
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA
| | - Eugene Y-X Chen
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA
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13
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Matsuoka SI, Fukumoto Y, Suzuki M. Tail-to-tail Cross-dimerization of Methyl Methacrylate/Methacrylonitrile with Acrylates Catalyzed by N-Heterocyclic Carbene. CHEM LETT 2017. [DOI: 10.1246/cl.170263] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Shin-ichi Matsuoka
- Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555
| | - Yuki Fukumoto
- Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555
| | - Masato Suzuki
- Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555
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14
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Zhu JB, Tang X, Falivene L, Caporaso L, Cavallo L, Chen EYX. Organocatalytic Coupling of Bromo-Lactide with Cyclic Ethers and Carbonates to Chiral Bromo-Diesters: NHC or Anion Catalysis? ACS Catal 2017. [DOI: 10.1021/acscatal.7b00794] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jian-Bo Zhu
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Xiaoyan Tang
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Laura Falivene
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Kaust Catalysis
Center, Thuwal 23955-6900, Saudi Arabia
| | - Lucia Caporaso
- Dipartimento
di Chimica e Biologia, Università di Salerno, Via Papa
Paolo Giovanni II, I-84084 Fisciano, Italy
| | - Luigi Cavallo
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Kaust Catalysis
Center, Thuwal 23955-6900, Saudi Arabia
| | - Eugene Y.-X. Chen
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
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Arrowsmith M, Böhnke J, Braunschweig H, Gao H, Légaré MA, Paprocki V, Seufert J. Synthesis and Reduction of Sterically Encumbered Mesoionic Carbene-Stabilized Aryldihaloboranes. Chemistry 2017; 23:12210-12217. [PMID: 28326622 DOI: 10.1002/chem.201700500] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Indexed: 01/26/2023]
Abstract
Sterically hindered, in situ generated 1,3,4-substituted 1,2,3-triazol-5-ylidene mesoionic carbenes (MICs) were employed to stabilize a number of aryl- and heteroaryldihaloboranes, as well as the first MIC-supported diborane. Reduction of borane adducts of the 1-(2,6-diisopropylphenyl)-3-methyl-4-tert-butyl-1,2,3-triazol-5-ylidene ligand with KC8 in non-coordinating solvents led to intramolecular C-H- and, C-C-activation at an isopropyl residue of the supporting ligand. DFT calculations showed that each of these activation reactions proceeds via a different isomer of a borylene intermediate.
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Affiliation(s)
- Merle Arrowsmith
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Julian Böhnke
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Holger Braunschweig
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Haopeng Gao
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Marc-André Légaré
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Valerie Paprocki
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Jens Seufert
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
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16
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Matsuoka SI, Kamijo Y, Suzuki M. Post-polymerization modification of unsaturated polyesters by Michael addition of N-heterocyclic carbenes. Polym J 2017. [DOI: 10.1038/pj.2017.2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Matsuoka SI, Awano N, Nakazawa M, Suzuki M. Tail-to-tail dimerization and Rauhut-Currier reaction of disubstituted Michael acceptors catalyzed by N-heterocyclic carbene. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.11.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Nakatake D, Yazaki R, Ohshima T. Chemoselective Transesterification of Acrylate Derivatives for Functionalized Monomer Synthesis Using a Hard Zinc Alkoxide Generation Strategy. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600737] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Daiki Nakatake
- Graduate school of Pharmaceutical Sciences; Kyushu University; Maidashi Higashi-ku 812-8582 Fukuoka Japan
| | - Ryo Yazaki
- Graduate school of Pharmaceutical Sciences; Kyushu University; Maidashi Higashi-ku 812-8582 Fukuoka Japan
| | - Takashi Ohshima
- Graduate school of Pharmaceutical Sciences; Kyushu University; Maidashi Higashi-ku 812-8582 Fukuoka Japan
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Gowda RR, Chen EYX. Organocatalytic and Chemoselective Polymerization of Multivinyl-Functionalized γ-Butyrolactones. ACS Macro Lett 2016; 5:772-776. [PMID: 35614656 DOI: 10.1021/acsmacrolett.6b00370] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Achieving complete chemoselectivity in the polymerization of multivinyl polar monomers is an important yet challenging task, currently achievable only by metal- or metalloid-mediated polymerization processes but in a noncatalytic fashion. Now this work shows that organic N-heterocyclic carbene (NHC) catalysts effect rapid, chemoselective, and catalytic polymerization of multivinyl-functionalized γ-butyrolactones, particularly γ-vinyl-α-methylene-γ-butyrolactone (VMBL). Thus, the NHC-catalyzed polymerization of VMBL not only is quantitatively chemoselective, proceeding exclusively via polyaddition across the conjugated α-methylene double bond while leaving the γ-vinyl double bond intact, but also requires only an exceptionally low catalyst loading of 50 ppm, thus, exhibiting a remarkably high catalyst turnover frequency of 80000 h-1 and producing on average 33.6 polymer chains of Mn = 73.8 kg/mol per NHC molecule. The resulting PVMBL can be either thermally cured into cross-linked materials or postfunctionalized with the thiol-ene "click" reaction to achieve complete conversion of the pendant vinyl group on every repeat unit into the corresponding thioether.
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Affiliation(s)
- Ravikumar R. Gowda
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Eugene Y.-X. Chen
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
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Hong M, Chen EYX. Towards Truly Sustainable Polymers: A Metal-Free Recyclable Polyester from Biorenewable Non-Strained γ-Butyrolactone. Angew Chem Int Ed Engl 2016; 55:4188-93. [DOI: 10.1002/anie.201601092] [Citation(s) in RCA: 166] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 02/14/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Miao Hong
- Department of Chemistry; Colorado State University; Fort Collins CO 80523-1872 USA
| | - Eugene Y.-X. Chen
- Department of Chemistry; Colorado State University; Fort Collins CO 80523-1872 USA
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Hong M, Chen EYX. Towards Truly Sustainable Polymers: A Metal-Free Recyclable Polyester from Biorenewable Non-Strained γ-Butyrolactone. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201601092] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Miao Hong
- Department of Chemistry; Colorado State University; Fort Collins CO 80523-1872 USA
| | - Eugene Y.-X. Chen
- Department of Chemistry; Colorado State University; Fort Collins CO 80523-1872 USA
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Hong M, Tang X, Falivene L, Caporaso L, Cavallo L, Chen EYX. Proton-Transfer Polymerization by N-Heterocyclic Carbenes: Monomer and Catalyst Scopes and Mechanism for Converting Dimethacrylates into Unsaturated Polyesters. J Am Chem Soc 2016; 138:2021-35. [PMID: 26779897 DOI: 10.1021/jacs.5b13019] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This contribution presents a full account of experimental and theoretical/computational investigations into the N-heterocyclic carbene (NHC)-catalyzed proton-transfer polymerization (HTP) that converts common dimethacrylates (DMAs) containing no protic groups into unsaturated polyesters. This new HTP proceeds through the step-growth propagation cycles via enamine intermediates, consisting of the proposed conjugate addition-proton transfer-NHC release fundamental steps. This study examines the monomer and catalyst scopes as well as the fundamental steps involved in the overall HTP mechanism. DMAs having six different types of linkages connecting the two methacrylates have been polymerized into the corresponding unsaturated polyesters. The most intriguing unsaturated polyester of the series is that based on the biomass-derived furfuryl dimethacrylate, which showed a unique self-curing ability. Four MeO- and Cl-substituted TPT (1,3,4-triphenyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene) derivatives as methanol insertion products, (Rx)TPT(MeO/H) (R = MeO, Cl; x = 2, 3), and two free carbenes (catalysts), (OMe2)TPT and (OMe3)TPT, have been synthesized, while (OMe2)TPT(MeO/H) and (OMe2)TPT have also been structurally characterized. The structure/reactivity relationship study revealed that (OMe2)TPT, being both a strong nucleophile and a good leaving group, exhibits the highest HTP activity and also produced the polyester with the highest Mn, while the Cl-substituted TPT derivatives are least active and efficient. Computational studies have provided mechanistic insights into the tail-to-tail dimerization coupling step as a suitable model for the propagation cycle of the HTP. The extensive energy profile was mapped out, and the experimentally observed unicity of the TPT-based catalysts was satisfactorily explained with the thermodynamic formation of key spirocyclic species.
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Affiliation(s)
- Miao Hong
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523-1872, United States
| | - Xiaoyan Tang
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523-1872, United States
| | - Laura Falivene
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Kaust Catalysis Center, Thuwal 23955-6900, Saudi Arabia.,Dipartimento di Chimica e Biologia, Università di Salerno , Via Papa Paolo Giovanni II, I-84084, Fisciano, Italy
| | - Lucia Caporaso
- Dipartimento di Chimica e Biologia, Università di Salerno , Via Papa Paolo Giovanni II, I-84084, Fisciano, Italy
| | - Luigi Cavallo
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Kaust Catalysis Center, Thuwal 23955-6900, Saudi Arabia.,Dipartimento di Chimica e Biologia, Università di Salerno , Via Papa Paolo Giovanni II, I-84084, Fisciano, Italy
| | - Eugene Y-X Chen
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523-1872, United States
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Kato T, Matsuoka SI, Suzuki M. N-Heterocyclic carbene-mediated redox condensation of alcohols. Chem Commun (Camb) 2016; 52:8569-72. [DOI: 10.1039/c6cc04154j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
N-Heterocyclic carbenes (NHCs) with a variety of oxidants promote the Mitsunobu-type coupling reactions of alcohols with phenols, carboxylic acids, and phthalimide.
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Affiliation(s)
- Terumasa Kato
- Department of Life Science and Applied Chemistry
- Graduate School of Engineering
- Nagoya Institute of Technology
- Nagoya
- Japan
| | - Shin-ichi Matsuoka
- Department of Life Science and Applied Chemistry
- Graduate School of Engineering
- Nagoya Institute of Technology
- Nagoya
- Japan
| | - Masato Suzuki
- Department of Life Science and Applied Chemistry
- Graduate School of Engineering
- Nagoya Institute of Technology
- Nagoya
- Japan
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