1
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Pham LD, Smith-Sweetser RO, Krupinsky B, Dewey CE, Lamb JR. Switchable Organocatalysis from N-heterocyclic Carbene-Carbodiimide Adducts with Tunable Release Temperature. Angew Chem Int Ed Engl 2023; 62:e202314376. [PMID: 37824288 DOI: 10.1002/anie.202314376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/10/2023] [Accepted: 10/12/2023] [Indexed: 10/14/2023]
Abstract
N-Heterocyclic carbenes (NHCs) are powerful organocatalysts, but practical applications often require in situ generation from stable precursors that "mask" the NHC reactivity via reversible binding. Previously established "masks" are often simple small molecules, such that the NHC structure is used to control both catalytic activity and activation temperature, leading to undesirable tradeoffs. Herein, we show that NHC-carbodiimide (CDI) adducts can be masked precursors for switchable organocatalysis and that the CDI substituents can control the reaction profile without changing the NHC structure. Large electronic variations on the CDI (e.g., alkyl versus aryl) drastically change the catalytically active temperature, whereas smaller perturbations (e.g., different para-substituted phenyls) tune the catalyst release within a narrower window. This control was demonstrated for three classic NHC-catalyzed reactions, each influencing the NHC-CDI equilibrium in different ways. Our results introduce a new paradigm for controlling NHC organocatalysis as well as present practical considerations for designing appropriate masks for various reactions.
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Affiliation(s)
- Le Dung Pham
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Red O Smith-Sweetser
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Briana Krupinsky
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Carolyn E Dewey
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Jessica R Lamb
- Department of Chemistry, University of Minnesota-Twin Cities, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
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2
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Zhang ZH, Wang X, Weng B, Zhang Y, Zhang G, Hong M. Zinc-Mediated Allylation-Lactonization One-Pot Reaction to Methylene Butyrolactones: Renewable Monomers for Sustainable Acrylic Polymers with Closed-Loop Recyclability. ACS POLYMERS AU 2022; 2:266-274. [PMID: 36855566 PMCID: PMC9955236 DOI: 10.1021/acspolymersau.2c00001] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Despite biomass-derived methylene butyrolactone monomers having great potential in substituting the petroleum-based methacrylates for synthesizing the sustainable acrylic polymers, the possible industrial production of these cyclic monomers is unfortunately not practical due to moderate overall yields and harsh reaction conditions or a time-consuming multistep process. Here we report a convenient and effective synthetic approach to a series of biomass-derived methylene butyrolactone monomers via a zinc-mediated allylation-lactonization one-pot reaction of biorenewable aldehydes with ethyl 2-(bromomethyl)acrylate. Under simple room-temperature sonication conditions, near-quantitative conversions (>90%) can be accomplished within 5-30 min, providing pure products with high isolated yields of 70-80%. Their efficient polymerizations with a high degree of control and complete chemoselectivity were enabled by the judiciously chosen Lewis pair catalyst based on methylaluminum bis(2,6-di-tert-butyl-4-methylphenoxide) [MeAl(BHT)2] Lewis acid and 3-diisopropyl-4,5-dimethylimidazol-2-ylidene (I i Pr) Lewis base, affording new poly(methylene butyrolactone)s with high thermal stability and thermal properties tuned in a wide range as well as pendant vinyl groups for postfunctionalization. Through the development of an effective depolymerization setup (370-390 °C, ca. 100 mTorr, 1 h, a muffle furnace), thermal depolymerizations of these polymers have been achieved with monomer recovery up to 99.8%, thus successfully constructing sustainable acrylic polymers with closed-loop recyclability.
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Affiliation(s)
- Zhen-Hua Zhang
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, University of Chinese
Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Xing Wang
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, University of Chinese
Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Biwei Weng
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, University of Chinese
Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yixin Zhang
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, University of Chinese
Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Guozhu Zhang
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, University of Chinese
Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Miao Hong
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, University of Chinese
Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China,School
of Chemistry and Material Sciences, Hangzhou Institute for Advanced
Study, University of Chinese Academy of
Sciences, 1 Sub-lane Xiangshan, Hangzhou 310024, China,
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3
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Sherman LM, Strausser SL, Borsari RK, Jenkins DM, Camden JP. Imidazolinium N-Heterocyclic Carbene Ligands for Enhanced Stability on Gold Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:5864-5871. [PMID: 33914540 DOI: 10.1021/acs.langmuir.1c00314] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
N-heterocyclic carbenes (NHCs) have emerged as versatile and robust ligands for noble metal surface modifications due to their ability to form compact, self-assembled monolayers. Despite a growing body of research, previous NHC surface modification schemes have employed just two structural motifs: the benzimidazolium NHC and the imidazolium NHC. However, different NHC moieties, including saturated NHCs, are often more effective in homogenous catalysis chemistry than these aforementioned motifs and may impart numerous advantages to NHC surfaces, such as increased stability and access to chiral groups. This work explores the preparation and stability of NHC-coated gold surfaces using imidazolium and imidazolinium NHC ligands. X-ray photoelectron spectroscopy and surface-enhanced Raman spectroscopy demonstrate the attachment of NHC ligands to the gold surface and show enhanced stability of imidazolinium compared to the traditional imidazolium under harsh acidic conditions.
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Affiliation(s)
- Lindy M Sherman
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, South Bend 46556, Indiana, United States
| | - Shelby L Strausser
- Department of Chemistry, University of Tennessee, Knoxville 37996, Tennessee, United States
| | - Rowan K Borsari
- Department of Chemistry, University of Tennessee, Knoxville 37996, Tennessee, United States
| | - David M Jenkins
- Department of Chemistry, University of Tennessee, Knoxville 37996, Tennessee, United States
| | - Jon P Camden
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, South Bend 46556, Indiana, United States
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4
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Nylund PVS, Ségaud NC, Albrecht M. Highly Modular Piano-Stool N-Heterocyclic Carbene Iron Complexes: Impact of Ligand Variation on Hydrosilylation Activity. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Pamela V. S. Nylund
- Department of Chemistry & Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Nathalie C. Ségaud
- Department of Chemistry & Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Martin Albrecht
- Department of Chemistry & Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
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5
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Ge F, Zhang Q, Wang X. Synthetic and mechanistic aspects of anionic polymerization of methyl methacrylate using tetrabutyl ammonium thioimidate. JOURNAL OF POLYMER SCIENCE 2021. [DOI: 10.1002/pol.20200824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Fang Ge
- College of Chemistry and Chemical Engineering Qingdao University Qingdao China
| | - Qun Zhang
- School of Chemical Engineering University of Chinese Academy of Sciences Beijing China
| | - Xiaowu Wang
- Chinese‐German Faculty for Engineering Qingdao University of Science and Technology Qingdao China
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6
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Souleymanou MY, El‐Ouahabi F, Masdeu‐Bultó AM, Godard C. Cooperative NHC‐based Catalytic System Immobilised onto Carbon Materials for the Cycloaddition of CO
2
to Epoxides. ChemCatChem 2021. [DOI: 10.1002/cctc.202001816] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Myriam Y. Souleymanou
- Department de Química Física i Inorgànica Universitat Rovira I Virgili C/ Marcel.lí Domingo s/n 43007 Tarragona Spain
| | - Fatima El‐Ouahabi
- Department de Química Física i Inorgànica Universitat Rovira I Virgili C/ Marcel.lí Domingo s/n 43007 Tarragona Spain
| | - Anna M. Masdeu‐Bultó
- Department de Química Física i Inorgànica Universitat Rovira I Virgili C/ Marcel.lí Domingo s/n 43007 Tarragona Spain
| | - Cyril Godard
- Department de Química Física i Inorgànica Universitat Rovira I Virgili C/ Marcel.lí Domingo s/n 43007 Tarragona Spain
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7
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Altmann HJ, Steinmann M, Elser I, Benedikter MJ, Naumann S, Buchmeiser MR. Dual catalysis with an
N
‐heterocyclic
carbene and a Lewis acid: Thermally latent
precatalyst
for the polymerization of
ε‐caprolactam. JOURNAL OF POLYMER SCIENCE 2020. [DOI: 10.1002/pol.20200502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Hagen J. Altmann
- Institute of Polymer Chemistry University of Stuttgart Stuttgart Germany
| | - Mark Steinmann
- German Institutes of Textile and Fiber Research Denkendorf Denkendorf Germany
| | - Iris Elser
- Institute of Polymer Chemistry University of Stuttgart Stuttgart Germany
| | | | - Stefan Naumann
- Institute of Polymer Chemistry University of Stuttgart Stuttgart Germany
| | - Michael R. Buchmeiser
- Institute of Polymer Chemistry University of Stuttgart Stuttgart Germany
- German Institutes of Textile and Fiber Research Denkendorf Denkendorf Germany
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8
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Altmann HJ, Frey W, Buchmeiser MR. A Spirocyclic Parabanic Acid Masked N-Heterocyclic Carbene as Thermally Latent Pre-Catalyst for Polyamide 6 Synthesis and Epoxide Curing. Macromol Rapid Commun 2020; 41:e2000338. [PMID: 32909339 DOI: 10.1002/marc.202000338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/14/2020] [Indexed: 11/06/2022]
Abstract
1,3-Dicyclcohexyl-6,9-dimethyl-1,3,6,9-tetraazaspiro[4.4]non-7-ene-2,4-dione, a spirocyclic parabanic acid derivative of N,N-dimethylimidazole, is used as thermally latent, protected N-heterocyclic carbene (NHC) in polymerizing anhydride-cured epoxide resins, and azepan-2-one, respectively. The protected carbene is synthesized from 1,3-dimethylimidazolium-2-carboxylate in the presence of two equivalents of cyclohexyl isocyanate. In the synthesis of epoxide resin thermosets, this class of latent NHC allows the production of fast and fully cured materials with high crosslinking content. Fast and complete conversion is found in the anionic ring opening polymerization (AROP) of azepan-2-one (ε-caprolactam, CLA) with and without additional activators.
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Affiliation(s)
- Hagen J Altmann
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, Stuttgart, 70569, Germany
| | - Wolfgang Frey
- Institute of Organic Chemistry, University of Stuttgart, Pfaffenwaldring 55, Stuttgart, 70569, Germany
| | - Michael R Buchmeiser
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, Stuttgart, 70569, Germany
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9
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Delaude L. The Chemistry of Azolium‐Carboxylate Zwitterions and Related Compounds: a Survey of the Years 2009–2020. Adv Synth Catal 2020. [DOI: 10.1002/adsc.202000639] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Lionel Delaude
- Laboratory of CatalysisMolSys Research UnitInstitut de Chimie Organique (B6a)Université de Liège Allée du six Août 13 4000 Liège Belgium
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10
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Köhler T, Gutacker A, Mejía E. Industrial synthesis of reactive silicones: reaction mechanisms and processes. Org Chem Front 2020. [DOI: 10.1039/d0qo01075h] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Silicones are used in many applications, from consumer products to medicinal and electronic devices. In this review we describe the most relevant reactions and industrial processes to furnish them, focusing specially on OH-terminated polysiloxanes.
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11
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Ségaud N, McMaster J, van Koten G, Albrecht M. Imidazolylidene Cu(II) Complexes: Synthesis Using Imidazolium Carboxylate Precursors and Structure Rearrangement Pathways. Inorg Chem 2019; 58:16047-16058. [PMID: 31714752 DOI: 10.1021/acs.inorgchem.9b02568] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Copper(II) complexes of type (NHC)CuX2 (X = OAc, Cl, Br, BF4, and NO3) bearing monodentate N-heterocyclic carbenes (NHCs) were prepared by in situ decarboxylation of imidazolium carboxylates as a new synthetic methodology for Cu(II)-NHC complexes. In contrast to the classical deprotonation method, the decarboxylation protocol does not require anaerobic conditions and provides access to complexes with NHCs that are unstable as free carbenes such as N,N'-diisopropyl-imidazolylidene and N,N'-dimethyl-imidazolylidene. Spectroscopic evidence of the formation of the Cu-CNHC bond is provided by UV-vis and EPR, in particular by the 44 MHz carbene hyperfine coupling constant using a 13C-labeled imidazolylidene ligand. A variation of the nature of the carbene N-substituents and the anions bound to the Cu(II) center is possible with this methodology. These variations strongly influence the stability of the complexes. Structural rearrangement and ligand reorganization was observed during recrystallization, which are comprised of heterolytic Cu-CNHC bond dissociation for unstable NHC ligands as well as homolytic Cu-X bond cleavage and disproportionation reactions depending on the nature of the anion X in the copper complex.
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Affiliation(s)
- Nathalie Ségaud
- Department of Chemistry & Biochemistry , University of Bern , Freiestrasse 3 , 3012 Bern , Switzerland
| | - Jonathan McMaster
- School of Chemistry , University of Nottingham, University Park , Nottingham NG7 2RD , United Kingdom
| | - Gerard van Koten
- Organic Chemistry and Catalysis, Debye Institute for Materials Science, Faculty of Science , Utrecht University , 3584CG Utrecht , The Netherlands
| | - Martin Albrecht
- Department of Chemistry & Biochemistry , University of Bern , Freiestrasse 3 , 3012 Bern , Switzerland
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12
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Zens A, Bauer F, Kolb B, Mannchen F, Seubert P, Forschner R, Flaig KS, Köhn A, Kunz D, Laschat S. Ni(NHC) Catalyzed Rearrangement of 1‐Acyl‐2‐vinylcyclopropanes: Tackling a Mechanistic Puzzle by Combined Experimental and Computational Studies. European J Org Chem 2019. [DOI: 10.1002/ejoc.201901096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Anna Zens
- Institut für Organische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Florian Bauer
- Institut für Theoretische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Benedikt Kolb
- Institut für Organische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Fabian Mannchen
- Institut für Organische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Philipp Seubert
- Institut für Organische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Robert Forschner
- Institut für Organische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Kim S. Flaig
- Institut für Anorganische Chemie Eberhard‐Karls‐Universität Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Andreas Köhn
- Institut für Theoretische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Doris Kunz
- Institut für Anorganische Chemie Eberhard‐Karls‐Universität Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Sabine Laschat
- Institut für Organische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
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13
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Bhattacharjee J, Harinath A, Sarkar A, Panda TK. Polymerization of ϵ‐Caprolactam to Nylon‐6 Catalyzed by Barium σ‐Borane Complex under Mild Condition. ChemCatChem 2019. [DOI: 10.1002/cctc.201900920] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jayeeta Bhattacharjee
- Department of ChemistryIndian Institute of Technology Hyderabad Kandi- 502 285, Sangareddy, Telangana India
| | - Adimulam Harinath
- Department of ChemistryIndian Institute of Technology Hyderabad Kandi- 502 285, Sangareddy, Telangana India
| | - Alok Sarkar
- Momentive Performance Materials Pvt. Ltd. Survey No. 09 Hosur Road, Electronic City (West) Bangalore- 560100 India
| | - Tarun K. Panda
- Department of ChemistryIndian Institute of Technology Hyderabad Kandi- 502 285, Sangareddy, Telangana India
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14
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Chang K, Dong Y, Xu X. Dihydrogen activation by intermolecular rare-earth aryloxide/N-heterocyclic carbene Lewis pairs. Chem Commun (Camb) 2019; 55:12777-12780. [DOI: 10.1039/c9cc06676d] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cooperative H2 activation can be readily achieved by combination of homoleptic rare-earth aryloxides with N-heterocyclic carbenes under mild conditions.
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Affiliation(s)
- Kejian Chang
- Key Laboratory of Organic Synthesis of Jiangsu Province
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
| | - Yifan Dong
- Key Laboratory of Organic Synthesis of Jiangsu Province
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
| | - Xin Xu
- Key Laboratory of Organic Synthesis of Jiangsu Province
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
- Suzhou 215123
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15
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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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16
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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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17
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Lu B, Zhu F, Wang D, Sun H, Shen Q. Iron-catalyzed esterification of allylic sp 3 C–H bonds with carboxylic acids: Facile access to allylic esters. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.05.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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18
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Naumann S, Mundsinger K, Cavallo L, Falivene L. N-Heterocyclic olefins as initiators for the polymerization of (meth)acrylic monomers: a combined experimental and theoretical approach. Polym Chem 2017. [DOI: 10.1039/c7py01226h] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The scope and mechanism of N-heterocyclic olefin-initiated polymerizations of acrylic monomers is investigated, including deactivation pathways.
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Affiliation(s)
- Stefan Naumann
- Department of Polymer Chemistry
- University of Stuttgart
- 70569 Stuttgart
- Germany
| | - Kai Mundsinger
- Department of Polymer Chemistry
- University of Stuttgart
- 70569 Stuttgart
- Germany
| | - Luigi Cavallo
- KAUST Catalysis Research Center
- King Abdullah University of Science and Technology
- Thuwal 23955-6900
- Saudi Arabia
| | - Laura Falivene
- KAUST Catalysis Research Center
- King Abdullah University of Science and Technology
- Thuwal 23955-6900
- Saudi Arabia
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19
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Katharina Reitz A, Sun Q, Wilhelm R, Kuckling D. The use of stable carbene-CO2adducts for the polymerization of trimethylene carbonate. ACTA ACUST UNITED AC 2016. [DOI: 10.1002/pola.28432] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Annika Katharina Reitz
- Department of Chemistry; University of Paderborn; Warburger Str. 100 33098 Paderborn Germany
| | - Qian Sun
- Department of Chemistry; University of Paderborn; Warburger Str. 100 33098 Paderborn Germany
| | - René Wilhelm
- Department of Chemistry; University of Paderborn; Warburger Str. 100 33098 Paderborn Germany
| | - Dirk Kuckling
- Department of Chemistry; University of Paderborn; Warburger Str. 100 33098 Paderborn Germany
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20
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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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21
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Ottou WN, Sardon H, Mecerreyes D, Vignolle J, Taton D. Update and challenges in organo-mediated polymerization reactions. Prog Polym Sci 2016. [DOI: 10.1016/j.progpolymsci.2015.12.001] [Citation(s) in RCA: 196] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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22
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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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23
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Naumann S, Klein J, Wang D, Buchmeiser MR. Convenient preparation of high molecular weight poly(dimethylsiloxane) using thermally latent NHC-catalysis: a structure-activity correlation. Beilstein J Org Chem 2015; 11:2261-6. [PMID: 26664650 PMCID: PMC4660969 DOI: 10.3762/bjoc.11.246] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 11/04/2015] [Indexed: 11/23/2022] Open
Abstract
The polymerization of octamethylcyclotetrasiloxane (D4) is investigated using several five-, six- and seven-membered N-heterocyclic carbenes (NHCs). The catalysts are delivered in situ from thermally susceptible CO2 adducts. It is demonstrated that the polymerization can be triggered from a latent state by mild heating, using the highly nucleophilic 1,3,4,5-tetramethylimidazol-2-ylidene as organocatalyst. This way, high molecular weight PDMS is prepared (up to >400 000 g/mol, 1.6 < Ð M < 2.5) in yields >95%, using low catalyst loadings (0.2-0.1 mol %). Furthermore, the results suggest that a nucleophilic, zwitterionic mechanism is in operation, in preference to purely anionic polymerization.
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Affiliation(s)
- Stefan Naumann
- Institute for Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Johannes Klein
- Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34–36, Berlin, Germany
| | - Dongren Wang
- Institute for Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Michael R Buchmeiser
- Institute for Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
- Institute of Textile Chemistry and Chemical Fibers, Körschtalstrasse 26, D-73770 Denkendorf, Germany
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24
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Ottou WN, Bourichon D, Vignolle J, Wirotius AL, Robert F, Landais Y, Sotiropoulos JM, Miqueu K, Taton D. From the N-Heterocyclic Carbene-Catalyzed Conjugate Addition of Alcohols to the Controlled Polymerization of (Meth)acrylates. Chemistry 2015; 21:9447-53. [PMID: 26013759 DOI: 10.1002/chem.201500594] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Indexed: 11/10/2022]
Abstract
Among various N-heterocyclic carbenes (NHCs) tested, only 1,3-bis(tert-butyl)imidazol-2-ylidene (NHC(tBu) ) proved to selectively promote the catalytic conjugate addition of alcohols onto (meth)acrylate substrates. This rather rare example of NHC-catalyzed 1,4-addition of alcohols was investigated as a simple means to trigger the polymerization of both methyl methacrylate and methyl acrylate (MMA and MA, respectively). Well-defined α-alkoxy poly(methyl (meth)acrylate) (PM(M)A) chains, the molar masses of which could be controlled by the initial [(meth)acrylate]0/[ROH]0 molar ratio, were ultimately obtained in N,N-dimethylformamide at 25 °C. A hydroxyl-terminated poly(ethylene oxide) (PEO-OH) macro-initiator was also employed to directly access PEO-b-PMMA amphiphilic block copolymers. Investigations into the reaction mechanism by DFT calculations revealed the occurrence of two competitive concerted pathways, involving either the activation of the alcohol or that of the monomer by NHC(tBu) .
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Affiliation(s)
- Winnie Nzahou Ottou
- CNRS/Univ. Bordeaux, LCPO, UMR 5629, 16 avenue Pey-Berland, 33607 Pessac cedex (France), Fax: (+33) 54-00-08-487
| | - Damien Bourichon
- CNRS/Univ. Pau&des Pays de l'Adour, IPREM, UMR 5254, 2 Avenue du Président P. Angot, 64053 Pau cedex 09 (France), Fax: (+33) 59-40-78-62
| | - Joan Vignolle
- CNRS/Univ. Bordeaux, LCPO, UMR 5629, 16 avenue Pey-Berland, 33607 Pessac cedex (France), Fax: (+33) 54-00-08-487
| | - Anne-Laure Wirotius
- CNRS/Univ. Bordeaux, LCPO, UMR 5629, 16 avenue Pey-Berland, 33607 Pessac cedex (France), Fax: (+33) 54-00-08-487
| | - Fredéric Robert
- CNRS/Univ. Bordeaux, ISM, UMR 5255, 351 cours de la Libération, 33400 Talence (France), Fax: (+33) 54-00-06-286
| | - Yannick Landais
- CNRS/Univ. Bordeaux, ISM, UMR 5255, 351 cours de la Libération, 33400 Talence (France), Fax: (+33) 54-00-06-286
| | - Jean-Marc Sotiropoulos
- CNRS/Univ. Pau&des Pays de l'Adour, IPREM, UMR 5254, 2 Avenue du Président P. Angot, 64053 Pau cedex 09 (France), Fax: (+33) 59-40-78-62
| | - Karinne Miqueu
- CNRS/Univ. Pau&des Pays de l'Adour, IPREM, UMR 5254, 2 Avenue du Président P. Angot, 64053 Pau cedex 09 (France), Fax: (+33) 59-40-78-62.
| | - Daniel Taton
- CNRS/Univ. Bordeaux, LCPO, UMR 5629, 16 avenue Pey-Berland, 33607 Pessac cedex (France), Fax: (+33) 54-00-08-487.
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25
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Matsuoka SI, Namera S, Suzuki M. Oxa-Michael addition polymerization of acrylates catalyzed by N-heterocyclic carbenes. Polym Chem 2015. [DOI: 10.1039/c4py01184h] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
N-heterocyclic carbenes (NHCs) smoothly catalyze the oxa-Michael addition polymerization of hydroxyl functionalized acrylate monomers at room temperature via a zwitterionic intermediate.
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Affiliation(s)
- Shin-ichi Matsuoka
- Department of Materials Science and Engineering
- Graduate School of Engineering
- Nagoya Institute of Technology
- Nagoya
- Japan
| | - Shoko Namera
- Department of Materials Science and Engineering
- Graduate School of Engineering
- Nagoya Institute of Technology
- Nagoya
- Japan
| | - Masato Suzuki
- Department of Materials Science and Engineering
- Graduate School of Engineering
- Nagoya Institute of Technology
- Nagoya
- Japan
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26
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Clough JM, Balan A, Sijbesma RP. Mechanochemical Reactions Reporting and Repairing Bond Scission in Polymers. Top Curr Chem (Cham) 2015; 369:209-38. [PMID: 26104999 DOI: 10.1007/128_2015_641] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
The past 10 years have seen a resurgence of interest in the field of polymer mechanochemistry. Whilst the destructive effects of mechanical force on polymer chains have been known for decades, it was only recently that researchers tapped into these forces to realize more useful chemical transformations. The current review discusses the strategic incorporation of weak covalent bonds in polymers to create materials with stress-sensing and damage-repairing properties. Firstly, the development of mechanochromism and mechanoluminescence as stress reporters is considered. The second half focuses on the net formation of covalent bonds as a response to mechanical force, via mechanocatalysis and mechanically unmasked chemical reactivity, and concludes with perspectives for the field.
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Affiliation(s)
- Jess M Clough
- Laboratory of Supramolecular Polymer Chemistry, Department of Chemical Engineering and Chemistry, Institute for Complex Molecular Systems, Eindhoven University of Technology, 513, 5600 MB, Eindhoven, The Netherlands
| | - Abidin Balan
- Laboratory of Supramolecular Polymer Chemistry, Department of Chemical Engineering and Chemistry, Institute for Complex Molecular Systems, Eindhoven University of Technology, 513, 5600 MB, Eindhoven, The Netherlands
| | - Rint P Sijbesma
- Laboratory of Supramolecular Polymer Chemistry, Department of Chemical Engineering and Chemistry, Institute for Complex Molecular Systems, Eindhoven University of Technology, 513, 5600 MB, Eindhoven, The Netherlands.
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27
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Naumann S, Dove AP. N-Heterocyclic carbenes as organocatalysts for polymerizations: trends and frontiers. Polym Chem 2015. [DOI: 10.1039/c5py00145e] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This review spotlights current areas of high interest for NHC-based polymerization research.
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28
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Hong M, Chen EYX. Proton-Transfer Polymerization (HTP): Converting Methacrylates to Polyesters by an N-Heterocyclic Carbene. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201406630] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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29
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Hong M, Chen EYX. Proton-Transfer Polymerization (HTP): Converting Methacrylates to Polyesters by an N-Heterocyclic Carbene. Angew Chem Int Ed Engl 2014; 53:11900-6. [DOI: 10.1002/anie.201406630] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 08/13/2014] [Indexed: 01/21/2023]
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30
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Buchmeiser MR, Sen S, Unold J, Frey W. N-heterocyclic carbene, high oxidation state molybdenum alkylidene complexes: functional-group-tolerant cationic metathesis catalysts. Angew Chem Int Ed Engl 2014; 53:9384-8. [PMID: 25123961 DOI: 10.1002/anie.201404655] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Indexed: 11/11/2022]
Abstract
We synthesized the first N-heterocyclic carbene (NHC) complexes of Schrock's molybdenum imido alkylidene bis(triflate) complexes. Unlike existing bis(triflate) complexes, the novel 16-electron complexes represent metathesis active, functional-group-tolerant catalysts. Single-crystal X-ray structures of two representatives of this novel class of Schrock catalysts are presented and reactivity is discussed in view of their structural peculiarities. In the presence of monomer (substrate), these catalysts form cationic species and can be employed in ring-closing metathesis (RCM), ring-opening metathesis polymerization (ROMP), as well as in the cyclopolymerization of α,ω-diynes. Monomers containing functional groups, which are not tolerated by the existing variations of Schrock's catalyst, e.g., sec-amine, hydroxy, and carboxylic acid moieties, can be used. These catalysts therefore hold great promise in both organic and polymer chemistry, where they allow for the use of protic monomers.
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Affiliation(s)
- Michael R Buchmeiser
- Institut für Polymerchemie, Universität Stuttgart, Pfaffenwaldring 55, 70550 Stuttgart (Germany) http://www.uni-stuttgart.de/ipoc/msf/index_en.html.
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31
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Buchmeiser MR, Sen S, Unold J, Frey W. Komplexe N-heterocyclischer Carbene mit Molybdän-Alkylidenen der höchsten Oxidationsstufe: funktionalitätstolerante kationische Katalysatoren für die Olefinmetathese. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201404655] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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32
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Naumann S, Speiser M, Schowner R, Giebel E, Buchmeiser MR. Air Stable and Latent Single-Component Curing of Epoxy/Anhydride Resins Catalyzed by Thermally Liberated N-Heterocyclic Carbenes. Macromolecules 2014. [DOI: 10.1021/ma501125k] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Stefan Naumann
- Institute
of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Maria Speiser
- Institute
of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Roman Schowner
- Institute
of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Elisabeth Giebel
- Institute of Textile Chemistry and Chemical Fibers, Körschtalstrasse 26, D-73770 Denkendorf, Germany
| | - Michael R. Buchmeiser
- Institute
of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
- Institute of Textile Chemistry and Chemical Fibers, Körschtalstrasse 26, D-73770 Denkendorf, Germany
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33
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Yang L, Wang H. Recent advances in carbon dioxide capture, fixation, and activation by using N-heterocyclic carbenes. CHEMSUSCHEM 2014; 7:962-998. [PMID: 24644039 DOI: 10.1002/cssc.201301131] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Indexed: 06/03/2023]
Abstract
In the last two decades, CO2 emission has caused a lot of environmental problems. To mitigate the concentration of CO2 in the atmosphere, various strategies have been implemented, one of which is the use of N-heterocyclic carbenes (NHCs) and related complexes to accomplish the capture, fixation, and activation of CO2 effectively. In this review, we summarize CO2 capture, fixation, and activation by utilizing NHCs and related complexes; homogeneous reactions and their reaction mechanisms are discussed. Free NHCs and NHC salts can capture CO2 in both direct and indirect ways to form imidazolium carboxylates, and they can also catalyze the reaction of aromatic aldehydes with CO2 to form carboxylic acids and derivatives. Moreover, associated with transition metals (TMs), NHCs can form NHC-TM complexes to transform CO2 into industrial acid or esters. Non-metal-NHC complexes can also catalyze the reactions of silicon and boron complexes with CO2 . In addition, catalytic cycloaddition of epoxides with CO2 is another effective function of NHC complexes, and NHC ionic liquids perform excellently in this aspect.
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Affiliation(s)
- Longhua Yang
- Institute for Advanced Study, Department of Chemistry, Nanchang University, Xuefu Dadao 999, Nanchang City, Jiangxi Province, 330031 (PR China)
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34
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Martin D, Canac Y, Lavallo V, Bertrand G. Comparative Reactivity of Different Types of Stable Cyclic and Acyclic Mono- and Diamino Carbenes with Simple Organic Substrates. J Am Chem Soc 2014; 136:5023-30. [DOI: 10.1021/ja412981x] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- David Martin
- UCSD-CNRS Joint Research Laboratory
(UMI 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0343, United States
| | - Yves Canac
- UCSD-CNRS Joint Research Laboratory
(UMI 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0343, United States
- Laboratoire de Chimie
de Coordination, (CNRS, UPR 8241), 31077 Toulouse, France
| | - Vincent Lavallo
- UCSD-CNRS Joint Research Laboratory
(UMI 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0343, United States
- Department of Chemistry, University of California at Riverside, Riverside, California 92521, United States
| | - Guy Bertrand
- UCSD-CNRS Joint Research Laboratory
(UMI 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0343, United States
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35
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Nzahou Ottou W, Bourichon D, Vignolle J, Wirotius AL, Robert F, Landais Y, Sotiropoulos JM, Miqueu K, Taton D. Cyclodimerization versus Polymerization of Methyl Methacrylate Induced byN-Heterocyclic Carbenes: A Combined Experimental and Theoretical Study. Chemistry 2014; 20:3989-97. [DOI: 10.1002/chem.201304492] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Indexed: 11/09/2022]
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36
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Naumann S, Buchmeiser MR. Latent and Delayed Action Polymerization Systems. Macromol Rapid Commun 2014; 35:682-701. [DOI: 10.1002/marc.201300898] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/08/2014] [Indexed: 01/01/2023]
Affiliation(s)
- Stefan Naumann
- Institute of Polymer Chemistry, University of Stuttgart; Pfaffenwaldring 55 D-70569 Stuttgart Germany
| | - Michael R. Buchmeiser
- Institute of Polymer Chemistry, University of Stuttgart; Pfaffenwaldring 55 D-70569 Stuttgart Germany
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37
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Naumann S, Buchmeiser MR. Liberation of N-heterocyclic carbenes (NHCs) from thermally labile progenitors: protected NHCs as versatile tools in organo- and polymerization catalysis. Catal Sci Technol 2014. [DOI: 10.1039/c4cy00344f] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The thermally triggered release of catalytically active, free NHCs from various heat-sensitive progenitors is discussed.
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Affiliation(s)
- Stefan Naumann
- Institute of Polymer Chemistry
- University of Stuttgart
- D-70569 Stuttgart, Germany
| | - Michael R. Buchmeiser
- Institute of Polymer Chemistry
- University of Stuttgart
- D-70569 Stuttgart, Germany
- Institute of Textile Chemistry and Chemical Fibres
- , Germany
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38
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Naumann S, Schmidt FG, Speiser M, Böhl M, Epple S, Bonten C, Buchmeiser MR. Anionic Ring-Opening Homo- and Copolymerization of Lactams by Latent, Protected N-Heterocyclic Carbenes for the Preparation of PA 12 and PA 6/12. Macromolecules 2013. [DOI: 10.1021/ma4018586] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Stefan Naumann
- Institute of Polymer
Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | | | - Maria Speiser
- Institute of Polymer
Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Margit Böhl
- Institute of Textile
Chemistry and Chemical Fibers, Körschtalstrasse 26, D-73770 Denkendorf, Germany
| | - Stefan Epple
- Institut
für Kunststofftechnik, University of Stuttgart, Böblingerstrasse
70, D-70199 Stuttgart, Germany
| | - Christian Bonten
- Institut
für Kunststofftechnik, University of Stuttgart, Böblingerstrasse
70, D-70199 Stuttgart, Germany
| | - Michael R. Buchmeiser
- Institute of Polymer
Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
- Institute of Textile
Chemistry and Chemical Fibers, Körschtalstrasse 26, D-73770 Denkendorf, Germany
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39
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Naumann S, Epple S, Bonten C, Buchmeiser MR. Polymerization of ε-Caprolactam by Latent Precatalysts Based on Protected N-Heterocyclic Carbenes. ACS Macro Lett 2013; 2:609-612. [PMID: 35581791 DOI: 10.1021/mz400199y] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The cyclic amide ε-caprolactam (ε-CLA) is efficiently polymerized by thermally latent C-2-protected N-heterocyclic carbenes (NHCs) to give the corresponding polyamide (PA 6). Carbon dioxide- and metal salt-protected NHCs were used as precatalysts, out of which the free carbenes were generated thermally. This way, a premixing of the corresponding initiator with ε-CLA was possible to yield a storable and directly polymerizable mixture. The screening of a variety of differently constituted carbenes showed the importance of basicity of the active species, thereby revealing N-alkyl-bearing tetrahydropyrimidinium-based carbenes as the most active ones. Rapid production of PA 6 in high yields was possible in bulk polymerization at 180 °C, the best activity displayed by 1,3-dicyclohexyltetrahydropyrimidinium-2-carboxylate (6-Cy-CO2). In situ rheology during polymerization showed the characteristics typical for the anionic polymerization of ε-CLA.
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Affiliation(s)
- Stefan Naumann
- Institute
of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569
Stuttgart, Germany
| | - Stefan Epple
- Institut
für Kunststofftechnik, University of Stuttgart, Böblingerstr. 70, D-70199
Stuttgart, Germany
| | - Christian Bonten
- Institut
für Kunststofftechnik, University of Stuttgart, Böblingerstr. 70, D-70199
Stuttgart, Germany
| | - Michael R. Buchmeiser
- Institute
of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569
Stuttgart, Germany
- Institute of Textile Chemistry and Chemical Fibers, Körschtalstr.
26, D-73770 Denkendorf, Germany
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Naumann S, Schmidt FG, Frey W, Buchmeiser MR. Protected N-heterocyclic carbenes as latent pre-catalysts for the polymerization of ε-caprolactone. Polym Chem 2013. [DOI: 10.1039/c3py00548h] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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