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Escayola S, Bahri-Laleh N, Poater A. % VBur index and steric maps: from predictive catalysis to machine learning. Chem Soc Rev 2024; 53:853-882. [PMID: 38113051 DOI: 10.1039/d3cs00725a] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Steric indices are parameters used in chemistry to describe the spatial arrangement of atoms or groups of atoms in molecules. They are important in determining the reactivity, stability, and physical properties of chemical compounds. One commonly used steric index is the steric hindrance, which refers to the obstruction or hindrance of movement in a molecule caused by bulky substituents or functional groups. Steric hindrance can affect the reactivity of a molecule by altering the accessibility of its reactive sites and influencing the geometry of its transition states. Notably, the Tolman cone angle and %VBur are prominent among these indices. Actually, steric effects can also be described using the concept of steric bulk, which refers to the space occupied by a molecule or functional group. Steric bulk can affect the solubility, melting point, boiling point, and viscosity of a substance. Even though electronic indices are more widely used, they have certain drawbacks that might shift preferences towards others. They present a higher computational cost, and often, the weight of electronics in correlation with chemical properties, e.g. binding energies, falls short in comparison to %VBur. However, it is worth noting that this may be because the steric index inherently captures part of the electronic content. Overall, steric indices play an important role in understanding the behaviour of chemical compounds and can be used to predict their reactivity, stability, and physical properties. Predictive chemistry is an approach to chemical research that uses computational methods to anticipate the properties and behaviour of these compounds and reactions, facilitating the design of new compounds and reactivities. Within this domain, predictive catalysis specifically targets the prediction of the performance and behaviour of catalysts. Ultimately, the goal is to identify new catalysts with optimal properties, leading to chemical processes that are both more efficient and sustainable. In this framework, %VBur can be a key metric for deepening our understanding of catalysis, emphasizing predictive catalysis and sustainability. Those latter concepts are needed to direct our efforts toward identifying the optimal catalyst for any reaction, minimizing waste, and reducing experimental efforts while maximizing the efficacy of the computational methods.
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Affiliation(s)
- Sílvia Escayola
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, c/Mª Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain.
- Donostia International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain
| | - Naeimeh Bahri-Laleh
- Iran Polymer and Petrochemical Institute (IPPI), P.O. Box 14965/115, Tehran, Iran
- Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM), Hiroshima University, Hiroshima, 739-8526, Japan
| | - Albert Poater
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, c/Mª Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain.
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2
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G M, Sharma D, Dandela R, Dhayalan V. Synthetic Strategies of N-Heterocyclic Olefin (NHOs) and Their Recent Application of Organocatalytic Reactions and Beyond. Chemistry 2023:e202302106. [PMID: 37605950 DOI: 10.1002/chem.202302106] [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: 07/03/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 08/23/2023]
Abstract
N-heterocyclic olefin (NHO) derivatives have an electron-rich as well as highly polarized carabon-carbon (C=C) double bond because of the electron-donating nature of nitrogen and sulphur atoms. While NHOs have been developing as novel organocatalysts and ligands for transition-metal complexes in various organic compound syntheses, different research groups are currently interested in preparing imidazole and triazolium-based chiral NHO catalysts. Some of them have been used for enantioselective organic transformations, but were still elusive. N-heterocyclic olefins, the alkylidene derivatives of N-heterocyclic carbenes (NHC), have shown promising results as effective promoters for numerous organic syntheses such as asymmetric catalysis, hydroborylation, hydrosilylation, reduction, CO2 sequestration, alkylation, cycloaddition, polymerization and the ring-opening reaction of aziridine and epoxides, esterification, C-F bond functionalization, amine coupling, trifluoromethyl thiolation, amination etc. NHOs catalysts with suitable structures can serve as a novel class of Lewis/Bronsted bases with strong basicity and high nucleophilicity properties.These facts strongly suggest their enormous chemical potential as sustainable catalysts for a wide variety of reactions in synthetic chemistry. The synthesis of NHOs and their properties are briefly reviewed in this article, along with a summary of the imidazole and triazole core of NHOs' most recent catalytic uses.
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Affiliation(s)
- Mahantesh G
- Department of Chemistry, National Institute of Technology Puducherry, Karaikal, 609609, Union Territory Puducherry, India
| | - Deepika Sharma
- Department of Industrial and Engineering Chemistry, Institute of Chemical Technology, Indian oil Odisha Campus, IIT, Kharagpur extension Centre Mouza Samantpuri, Bhubaneswar, 751013, Odisha, India
| | - Rambabu Dandela
- Department of Industrial and Engineering Chemistry, Institute of Chemical Technology, Indian oil Odisha Campus, IIT, Kharagpur extension Centre Mouza Samantpuri, Bhubaneswar, 751013, Odisha, India
| | - Vasudevan Dhayalan
- Department of Chemistry, National Institute of Technology Puducherry, Karaikal, 609609, Union Territory Puducherry, India
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3
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Wanjari PJ, Saha N, Dubey G, Bharatam PV. Metal-free methods for the generation of benzimidazoles and 2-aminobenzimidazoles. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.133143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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4
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Zhao W, Li F, Li C, He J, Zhang Y, Chen C. Lewis Pair Catalyzed Regioselective Polymerization of (E,E)-Alkyl Sorbates for the Synthesis of (AB) n Sequenced Polymers. Angew Chem Int Ed Engl 2021; 60:24306-24311. [PMID: 34510679 DOI: 10.1002/anie.202111336] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Indexed: 01/17/2023]
Abstract
In this contribution, Lewis pairs (LPs) composed of N-heterocyclic olefins (NHOs) with different steric hindrance and nucleophilicity as Lewis bases (LBs) and Al-based compounds with comparable acidity but different steric hindrance as Lewis acids (LAs) were applied for 1,4-selective polymerization of (E,E)-methyl sorbate (MS) and (E,E)-ethyl sorbate (ES). The effects of steric hindrance, electron-donating ability, and acidity of LPs on MS and ES polymerization were systematically investigated. High catalytic activity and high initiation efficiency can be achieved, leading to the formation of PMS with 100 % 1,4-selectivity, tunable molecular weight (Mw up to 333 kg mol-1 ), and narrow molecular weight distribution (MWD). Block copolymerization of ES and methyl methacrylate (MMA) was also realized. Meanwhile, this system can be applied to other homologous conjugated diene substrates. Furthermore, simple chemical reactions can efficiently convert PMS to different polymers with strict (AB)n sequence structures, such as poly(sorbic acid), poly(propylene-alt-methyl acrylate), poly(propylene-alt-acrylic acid), poly(propylene-alt-allyl alcohol), and poly(ethylene-alt-2-butylene).
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Affiliation(s)
- Wuchao Zhao
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin, 130012, P. R. China
| | - Fukuan Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin, 130012, P. R. China
| | - Chengkai Li
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Jianghua He
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin, 130012, P. R. China
| | - Yuetao Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin, 130012, P. R. China
| | - Changle Chen
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
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5
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Zhao W, Li F, Li C, He J, Zhang Y, Chen C. Lewis Pair Catalyzed Regioselective Polymerization of (
E
,
E
)‐Alkyl Sorbates for the Synthesis of (AB)
n
Sequenced Polymers. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202111336] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Wuchao Zhao
- State Key Laboratory of Supramolecular Structure and Materials College of Chemistry Jilin University, Changchun Jilin 130012 P. R. China
| | - Fukuan Li
- State Key Laboratory of Supramolecular Structure and Materials College of Chemistry Jilin University, Changchun Jilin 130012 P. R. China
| | - Chengkai Li
- CAS Key Laboratory of Soft Matter Chemistry Hefei National Laboratory for Physical Sciences at the Microscale Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026 P. R. China
| | - Jianghua He
- State Key Laboratory of Supramolecular Structure and Materials College of Chemistry Jilin University, Changchun Jilin 130012 P. R. China
| | - Yuetao Zhang
- State Key Laboratory of Supramolecular Structure and Materials College of Chemistry Jilin University, Changchun Jilin 130012 P. R. China
| | - Changle Chen
- CAS Key Laboratory of Soft Matter Chemistry Hefei National Laboratory for Physical Sciences at the Microscale Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026 P. R. China
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6
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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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7
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Wang Z, Niu QH, Xue XS, Ji P. The Brönsted Basicities of N-Heterocyclic Olefins in DMSO: An Effective Way to Evaluate the Stability of NHO-CO 2 Adducts. J Org Chem 2020; 85:13204-13210. [PMID: 32900190 DOI: 10.1021/acs.joc.0c01987] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A Brönsted basicity scale (∼24 pK units) for 85 commonly seen imidazole-, imidazoline-, triazole-, and thiazole-based N-heterocyclic olefins (NHOs) in DMSO was established using a well-examined computational model. The influence of substituents on the Brönsted basicities of these NHOs was investigated through basicity comparisons and rationalized by geometric analyses. The Gibbs energy (ΔGr) of the reaction between NHO and CO2 was also calculated, which linearly correlates with the basicity of the corresponding NHO, suggesting that the stability of NHO-CO2 adducts can be evaluated by the basicity of NHOs and a stronger basicity leads to a more stable NHO-CO2 adduct.
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Affiliation(s)
- Zhen Wang
- Henan Joint International Research Laboratory of Nanocomposite Sensing Materials, School of Chemical and Environmental Engineering, Anyang Institute of Technology, Anyang 455000, China
| | - Qian-Hang Niu
- Henan Joint International Research Laboratory of Nanocomposite Sensing Materials, School of Chemical and Environmental Engineering, Anyang Institute of Technology, Anyang 455000, China
| | - Xiao-Song Xue
- Henan Joint International Research Laboratory of Nanocomposite Sensing Materials, School of Chemical and Environmental Engineering, Anyang Institute of Technology, Anyang 455000, China.,State Key Laboratory on Elemento-Organic Chemistry, Department of Chemistry, Nankai University, Tianjin 300071, China
| | - Pengju Ji
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing 100084, China
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8
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von Seggern N, Schindler T, Naumann S. Dual Catalytic Ring-Opening Polymerization of Ethylene Carbonate for the Preparation of Degradable PEG. Biomacromolecules 2020; 21:2661-2669. [DOI: 10.1021/acs.biomac.0c00360] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Nils von Seggern
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Tamara Schindler
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Stefan Naumann
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
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9
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Watson IC, Zhou Y, Ferguson MJ, Kränzlein M, Rieger B, Rivard E. Trialkylaluminum N‐Heterocyclic Olefin (NHO) Adducts as Catalysts for the Polymerization of Michael‐Type Monomers. Z Anorg Allg Chem 2020. [DOI: 10.1002/zaac.201900331] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Ian C. Watson
- Department of Chemistry University of Alberta 11227 Saskatchewan Drive T6G 2G2 Edmonton Alberta Canada
| | - Yuqiao Zhou
- Department of Chemistry University of Alberta 11227 Saskatchewan Drive T6G 2G2 Edmonton Alberta Canada
| | - Michael J. Ferguson
- Department of Chemistry University of Alberta 11227 Saskatchewan Drive T6G 2G2 Edmonton Alberta Canada
| | - Moritz Kränzlein
- Catalysis Research Center & WACKER‐Chair of Macromolecular Chemistry Technical University of Munich Lichtenbergstrasse 4 85748 Garching Germany
| | - Bernhard Rieger
- Catalysis Research Center & WACKER‐Chair of Macromolecular Chemistry Technical University of Munich Lichtenbergstrasse 4 85748 Garching Germany
| | - Eric Rivard
- Department of Chemistry University of Alberta 11227 Saskatchewan Drive T6G 2G2 Edmonton Alberta Canada
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10
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Markus F, Bruckner JR, Naumann S. Controlled Synthesis of “Reverse Pluronic”‐Type Block Copolyethers with High Molar Masses for the Preparation of Hydrogels with Improved Mechanical Properties. MACROMOL CHEM PHYS 2020. [DOI: 10.1002/macp.201900437] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Felix Markus
- Institute of Polymer ChemistryUniversity of Stuttgart 70569 Stuttgart Germany
| | - Johanna R. Bruckner
- Institute of Physical ChemistryUniversity of Stuttgart 70569 Stuttgart Germany
| | - Stefan Naumann
- Institute of Polymer ChemistryUniversity of Stuttgart 70569 Stuttgart Germany
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11
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Suzuki M, Kaneko T, Ishikawa Y, Matsuoka SI. Anionic polymerization of acrylic thioester by using organic base. Polym Chem 2020. [DOI: 10.1039/c9py01621j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
An acrylic thioester is polymerized with organic bases as the initiators via zwitterionic mechanisms involving propagation at the anionic sites.
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Affiliation(s)
- Masato Suzuki
- Department of Life Science and Applied Chemistry
- Nagoya Institute of Technology
- Nagoya 466-8555
- Japan
| | - Takumi Kaneko
- Department of Life Science and Applied Chemistry
- Nagoya Institute of Technology
- Nagoya 466-8555
- Japan
| | - Yuna Ishikawa
- Department of Life Science and Applied Chemistry
- Nagoya Institute of Technology
- Nagoya 466-8555
- Japan
| | - Shin-ichi Matsuoka
- Department of Life Science and Applied Chemistry
- Nagoya Institute of Technology
- Nagoya 466-8555
- Japan
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12
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Li C, Zhao W, He J, Zhang Y. Highly efficient cyclotrimerization of isocyanates using N-heterocyclic olefins under bulk conditions. Chem Commun (Camb) 2019; 55:12563-12566. [PMID: 31577293 DOI: 10.1039/c9cc06402h] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
With a catalyst loading as low as 0.005%, high to excellent yields of isocyanurates could be achieved from N-heterocyclic olefin mediated organocatalytic cyclotrimerization of a wide range of isocyanates under bulk conditions. Experimental details coupled with structural characterization of the key intermediates led to comprehensive mechanistic studies of cyclotrimerization.
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Affiliation(s)
- Chengkai Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012, China.
| | - Wuchao Zhao
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012, China.
| | - Jianghua He
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012, China.
| | - Yuetao Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012, China.
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13
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Naumann S. Synthesis, properties & applications of N-heterocyclic olefins in catalysis. Chem Commun (Camb) 2019; 55:11658-11670. [PMID: 31517349 DOI: 10.1039/c9cc06316a] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
N-Heterocyclic olefins (NHOs), a recently (re-)discovered type of electron-rich, polar alkene, are comprehensively presented. Along with synthetic aspects and chemical properties, special emphasis is put on the multi-faceted impact NHOs already have had on catalysis. This is discussed along the lines of small molecule organocatalysis, organo- and metal-assisted polymerization and of the understanding and application of NHO-ligated organometallic complexes. Highlighted are the strong basicity of NHOs ("superbases"), their high nucleophilicity and the design principles to tailor NHO (organo-)catalysts. It is demonstrated that NHOs can complement, and in many cases out-perform, the much better established N-heterocyclic carbene-based systems. Examples include among others CO2-sequestration, the polymerization of lactones and epoxides or the transfer hydrogenation of carbonyls. Further, the unique ability to selectively address basic or nucleophilic reaction pathways via NHO-mediation is detailed, as is the bonding situation in NHO-metal complexes and the ability of the olefin to act as an electronically flexible ligand.
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Affiliation(s)
- Stefan Naumann
- University of Stuttgart, Institute of Polymer Chemistry, 70569 Stuttgart, Germany.
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14
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Zhang X, Wang L, Wang Q, Ge F, Wang X. Synthesis, Characterization of Pyridyl Heterocyclic Olefins (PHOs) and Activation of Heterocumulenes. ChemistrySelect 2019. [DOI: 10.1002/slct.201902563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Xianhui Zhang
- Key Laboratory of Biobased MaterialsQingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of Sciences 189 Songling Road Qingdao 266101 China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of Sciences Beijing 10049 China
| | - Liang Wang
- Key Laboratory of Biobased MaterialsQingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of Sciences 189 Songling Road Qingdao 266101 China
| | - Qinggang Wang
- Key Laboratory of Biobased MaterialsQingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of Sciences 189 Songling Road Qingdao 266101 China
| | - Fang Ge
- College of Chemistry and Chemical EngineeringQingdao University Shandong 266071 China
| | - Xiaowu Wang
- Key Laboratory of Biobased MaterialsQingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of Sciences 189 Songling Road Qingdao 266101 China
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15
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Walther P, Krauß A, Naumann S. Lewis Pair Polymerization of Epoxides via Zwitterionic Species as a Route to High-Molar-Mass Polyethers. Angew Chem Int Ed Engl 2019; 58:10737-10741. [PMID: 31099454 DOI: 10.1002/anie.201904806] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Indexed: 11/08/2022]
Abstract
A dual catalytic setup based on N-heterocyclic olefins (NHOs) and magnesium bis(hexamethyldisilazide) (Mg(HMDS)2 ) was used to prepare poly(propylene oxide) with a molar mass (Mn ) >500 000 g mol-1 , in some cases even >106 g mol-1 , as determined by GPC/light scattering. This is achieved by combining the rapid polymerization characteristics of a zwitterionic, Lewis pair type mechanism with the efficient epoxide activation by the MgII species. Transfer-to-monomer, traditionally frustrating attempts at synthesizing polyethers with a high degree of polymerization, is practically removed as a limiting factor by this approach. NMR and MALDI-ToF MS experiments reveal key aspects of the proposed mechanism, whereby the polymerization is initiated via nucleophilic attack by the NHO on the activated monomer, generating a zwitterionic species. This strategy can also be extended to other epoxides, including functionalized monomers.
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Affiliation(s)
- Patrick Walther
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Annabelle Krauß
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Stefan Naumann
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
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Walther P, Krauß A, Naumann S. Darstellung von hochmolekularen Polyethern durch die zwitterionische Lewis‐Paar‐Polymerisation von Epoxiden. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201904806] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Patrick Walther
- Institut für PolymerchemieUniversität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Deutschland
| | - Annabelle Krauß
- Institut für PolymerchemieUniversität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Deutschland
| | - Stefan Naumann
- Institut für PolymerchemieUniversität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Deutschland
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17
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Schuldt R, Kästner J, Naumann S. Proton Affinities of N-Heterocyclic Olefins and Their Implications for Organocatalyst Design. J Org Chem 2019; 84:2209-2218. [DOI: 10.1021/acs.joc.8b03202] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Robin Schuldt
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Johannes Kästner
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Stefan Naumann
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
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18
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Zhou L, Xu G, Mahmood Q, Lv C, Wang X, Sun X, Guo K, Wang Q. N-Heterocyclic olefins and thioureas as an efficient cooperative catalyst system for ring-opening polymerization of δ-valerolactone. Polym Chem 2019. [DOI: 10.1039/c9py00018f] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
An organocatalytic ring-opening polymerization of δ-valerolactone has been developed.
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Affiliation(s)
- Li Zhou
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- China
| | - Guangqiang Xu
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- China
| | - Qaiser Mahmood
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- China
| | - Chengdong Lv
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- China
| | - Xiaowu Wang
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- China
| | - Xitong Sun
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- China
| | - Kai Guo
- State Key Laboratory of Materials-Oriented Chemical Engineering
- College of Biotechnology and Pharmaceutical Engineering
- Nanjing Tech University
- Nanjing
- China
| | - Qinggang Wang
- Key Laboratory of Biobased Materials
- Qingdao Institute of Bioenergy and Bioprocess Technology
- Chinese Academy of Sciences
- Qingdao
- China
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19
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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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20
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Meisner J, Karwounopoulos J, Walther P, Kästner J, Naumann S. The Lewis Pair Polymerization of Lactones Using Metal Halides and N-Heterocyclic Olefins: Theoretical Insights. Molecules 2018; 23:E432. [PMID: 29462873 PMCID: PMC6017504 DOI: 10.3390/molecules23020432] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/12/2018] [Accepted: 02/12/2018] [Indexed: 12/05/2022] Open
Abstract
Lewis pair polymerization employing N-Heterocyclic olefins (NHOs) and simple metal halides as co-catalysts has emerged as a useful tool to polymerize diverse lactones. To elucidate some of the mechanistic aspects that remain unclear to date and to better understand the impact of the metal species, computational methods have been applied. Several key aspects have been considered: (1) the formation of NHO-metal halide adducts has been evaluated for eight different NHOs and three different Lewis acids, (2) the coordination of four lactones to MgCl₂ was studied and (3) the deprotonation of an initiator (butanol) was investigated in the presence and absence of metal halide for one specific Lewis pair. It was found that the propensity for adduct formation can be influenced, perhaps even designed, by varying both organic and metallic components. Apart from the NHO backbone, the substituents on the exocyclic, olefinic carbon have emerged as interesting tuning site. The tendency to form adducts is ZnCl₂ > MgCl₂ > LiCl. If lactones coordinate to MgCl₂, the most likely binding mode is via the carbonyl oxygen. A chelating coordination cannot be ruled out and seems to gain importance upon increasing ring-size of the lactone. For a representative NHO, it is demonstrated that in a metal-free setting an initiating alcohol cannot be deprotonated, while in the presence of MgCl₂ the same process is exothermic with a low barrier.
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Affiliation(s)
- Jan Meisner
- Institute of Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
| | - Johannes Karwounopoulos
- Institute of Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
| | - Patrick Walther
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
| | - Johannes Kästner
- Institute of Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
| | - Stefan Naumann
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
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21
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Walther P, Frey W, Naumann S. Polarized olefins as enabling (co)catalysts for the polymerization of γ-butyrolactone. Polym Chem 2018. [DOI: 10.1039/c8py00784e] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
N-Heterocyclic olefins (NHOs) can homopolymerize GBL via anionic or zwitterionic pathways, whereby polymerization mode and polymer topology depend on the chemical structure of the NHO and the presence of LiCl as cocatalyst.
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Affiliation(s)
- Patrick Walther
- University of Stuttgart
- Institute of Polymer Chemistry
- 70569 Stuttgart
- Germany
| | - Wolfgang Frey
- University of Stuttgart
- Institute of Organic Chemistry
- 70569 Stuttgart
- Germany
| | - Stefan Naumann
- University of Stuttgart
- Institute of Polymer Chemistry
- 70569 Stuttgart
- Germany
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22
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Balint A, Papendick M, Clauss M, Müller C, Giesselmann F, Naumann S. Controlled preparation of amphiphilic triblock-copolyether in a metal- and solvent-free approach for tailored structure-directing agents. Chem Commun (Camb) 2018; 54:2220-2223. [DOI: 10.1039/c7cc09031e] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Organocatalysis is employed as a precise tool for the preparation of triblock-copolyethers for a systematic access to structure-direction.
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Affiliation(s)
- Alexander Balint
- University of Stuttgart
- Institute for Polymer Chemistry
- 70569 Stuttgart
- Germany
| | - Marius Papendick
- University of Stuttgart
- Institute for Polymer Chemistry
- 70569 Stuttgart
- Germany
| | - Manuel Clauss
- German Institutes of Textile and Fiber Research
- 73770 Denkendorf
- Germany
| | - Carsten Müller
- University of Stuttgart
- Institute for Physical Chemistry
- 70569 Stuttgart
- Germany
| | - Frank Giesselmann
- University of Stuttgart
- Institute for Physical Chemistry
- 70569 Stuttgart
- Germany
| | - Stefan Naumann
- University of Stuttgart
- Institute for Polymer Chemistry
- 70569 Stuttgart
- Germany
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23
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Walther P, Naumann S. N-Heterocyclic Olefin-Based (Co)polymerization of a Challenging Monomer: Homopolymerization of ω-Pentadecalactone and Its Copolymers with γ-Butyrolactone, δ-Valerolactone, and ε-Caprolactone. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b01678] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Patrick Walther
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - Stefan Naumann
- Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
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