1
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Li K, Cheng JL, Wang MY, Xiong W, Huang HY, Feng LW, Cai Z, Zhu JB. Kinetic Resolution Polymerization Enabled Chemical Synthesis of Perfectly Isotactic Polythioesters. Angew Chem Int Ed Engl 2024; 63:e202405382. [PMID: 38682252 DOI: 10.1002/anie.202405382] [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: 03/19/2024] [Revised: 04/28/2024] [Accepted: 04/29/2024] [Indexed: 05/01/2024]
Abstract
Isotactic polythioesters (PTEs) that are thioester analogs to natural polyhydroxyalkanoates (PHAs) have attracted growing attention due to their distinct properties. However, the development of chemically synthetic methods for preparing isotactic PTEs has long been an intricate endeavour. Herein, we report the successful synthesis of perfectly isotactic PTEs via stereocontrolled ring-opening polymerization. This binaphthalene-salen aluminium (SalBinam-Al) catalyst promoted a robust polymerization of rac-α-substituted-β-propiothiolactones (rac-BTL and rac-PTL) with highly kinetic resolution, affording perfectly isotactic P(BTL) and P(PTL) with Mn up to 276 kDa. Impressively, the isotactic P(BTL) formed a supramolecular stereocomplex with improved thermal property (Tm=204 °C). Ultimately, this kinetic resolution polymerization enabled the facile isolation of enantiopure (S)-BTL, which could efficiently convert to an important pharmaceutical building block (S)-2-benzyl-3-mercapto-propanoic acid. Isotactic P(PTL) served as a tough and ductile material comparable to the commercialized polyolefins. This synthetic system allowed to access of isotactic PTEs, establishing a powerful platform for the discovery of sustainable plastics.
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Affiliation(s)
- Kun Li
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan) College of Chemistry, Sichuan University, 29 Wangjiang Rd, Chengdu, 610064, P. R. China
| | - Jing-Liang Cheng
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Meng-Yuan Wang
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan) College of Chemistry, Sichuan University, 29 Wangjiang Rd, Chengdu, 610064, P. R. China
| | - Wei Xiong
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan) College of Chemistry, Sichuan University, 29 Wangjiang Rd, Chengdu, 610064, P. R. China
| | - Hao-Yi Huang
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan) College of Chemistry, Sichuan University, 29 Wangjiang Rd, Chengdu, 610064, P. R. China
| | - Liang-Wen Feng
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Zhongzheng Cai
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan) College of Chemistry, Sichuan University, 29 Wangjiang Rd, Chengdu, 610064, P. R. China
| | - Jian-Bo Zhu
- National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan) College of Chemistry, Sichuan University, 29 Wangjiang Rd, Chengdu, 610064, P. R. China
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2
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Zhu Y, Tao Y. Stereoselective Ring-opening Polymerization of S-Carboxyanhydrides Using Salen Aluminum Catalysts: A Route to High-Isotactic Functionalized Polythioesters. Angew Chem Int Ed Engl 2024; 63:e202317305. [PMID: 38179725 DOI: 10.1002/anie.202317305] [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: 11/14/2023] [Revised: 12/28/2023] [Accepted: 01/03/2024] [Indexed: 01/06/2024]
Abstract
Polythioesters are important sustainable polymers with broad applications. The ring-opening polymerization (ROP) of S-Carboxyanhydrides (SCAs) can afford polythioesters with functional groups that are typically difficult to prepare by ROP of thiolactones. Typical methods involving organocatalysts, like dimethylaminopyridine (DMAP) and triethylamine (Et3 N), have been plagued by uncontrolled polymerization, including epimerization for most SCAs resulting in the loss of isotacticity. Here, we report the use of salen aluminum catalysts for the selective ROP of various SCAs without epimerization, affording functionalized polythioester with high molecular weight up to 37.6 kDa and the highest Pm value up to 0.99. Notably, the ROP of TlaSCA (SCA prepared from thiolactic acid) generates the first example of a isotactic crystalline poly(thiolactic acid), which exhibited a distinct Tm value of 152.6 °C. Effective ligand tailoring governs the binding affinity between the sulfide chain-end and the metal center, thereby maintaining the activity of organometallic catalysts and reducing the occurrence of epimerization reactions.
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Affiliation(s)
- Yinuo Zhu
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun, 130022, P. R. China
- University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Youhua Tao
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun, 130022, P. R. China
- University of Science and Technology of China, Hefei, 230026, P. R. China
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3
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Clarke RW, Caputo MR, Polo Fonseca L, McGraw ML, Reilly LT, Franklin KA, Müller AJ, Chen EYX. Cyclic and Linear Tetrablock Copolymers Synthesized at Speed and Scale by Lewis Pair Polymerization of a One-Pot (Meth)acrylic Mixture and Characterized at Multiple Levels. J Am Chem Soc 2024; 146:4930-4941. [PMID: 38346332 DOI: 10.1021/jacs.3c14136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Cyclic block copolymers (cBCP) are fundamentally intriguing materials, but their synthetic challenges that demand precision in controlling both the monomer sequence and polymer topology limit access to AB and ABC block architectures. Here, we show that cyclic ABAB tetra-BCPs (cABAB) and their linear counterpart (lABAB) can be readily obtained at a speed and scale from one-pot (meth)acrylic monomer mixtures, through coupling the Lewis pair polymerization's unique compounded-sequence control with its precision in topology control. This approach achieves fast (<15 min) and quantitative (>99%) conversion to tetra-BCPs of predesignated linear or cyclic topology at scale (40 g) in a one-pot procedure, precluding the needs for repeated chain extensions, stoichiometric addition steps, dilute conditions, and postsynthetic modifications, and/or postsynthetic ring-closure steps. The resulting lABAB and cABAB have essentially identical molecular weights (Mn = 165-168 kg mol-1) and block degrees/symmetry, allowing for direct behavioral comparisons in solution (hydrodynamic volume, intrinsic viscosity, elution time, and refractive indices), bulk (thermal transitions), and film (thermomechanical and rheometric properties and X-ray scattering patterns) states. To further the morphological characterizations, allylic side-chain functionality is exploited via the thiol-ene click chemistry to install crystalline octadecane side chains and promote phase separation between the A and B blocks, allowing visualization of microdomain formation.
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Affiliation(s)
- Ryan W Clarke
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Maria Rosaria Caputo
- Polymat and Department of Polymers and Advanced Materials: Physics, Chemistry and Technology, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel de Lardizabal 3, Donostia-San Sebastián 20018, Spain
| | - Lucas Polo Fonseca
- Polymat and Department of Polymers and Advanced Materials: Physics, Chemistry and Technology, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel de Lardizabal 3, Donostia-San Sebastián 20018, Spain
| | - Michael L McGraw
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Liam T Reilly
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Kevin A Franklin
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Alejandro J Müller
- Polymat and Department of Polymers and Advanced Materials: Physics, Chemistry and Technology, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel de Lardizabal 3, Donostia-San Sebastián 20018, Spain
- IKERBASQUE, Basque Foundation for Science, Plaza Euskadi 5, Bilbao 48009, Spain
| | - Eugene Y-X Chen
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
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4
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Lu X, Zhang X, Zhang C, Zhang X. Cyclic Polyesters with Closed-Loop Recyclability from A New Chemically Reversible Alternating Copolymerization. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306072. [PMID: 38037295 PMCID: PMC10811513 DOI: 10.1002/advs.202306072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 11/14/2023] [Indexed: 12/02/2023]
Abstract
Polyesters with both cyclic topology and chemical recyclability are attractive. Here, the alternating copolymerization of cyclic anhydride and o-phthalaldehyde to synthesize a series of cyclic and recyclable polyesters are reported for the first time. Besides readily available monomers, the copolymerization is carried out at 25 °C, uses common Lewis/Brønsted acids as catalysts, and achieves high yields within 1 h. The resulting polyesters possess well-defined alternating sequences, high-purity cyclic topology, and tunable structures using distinct two monomer sets. Of interest, the copolymerization manifests obvious chemical reversibility as revealed by kinetic and thermodynamic studies, making the unprecedented polyesters easy to recycle to their distinct two monomers in a closed loop at high temperatures. This work furnishes a facile and efficient method to synthesize cyclic polyesters with closed-loop recyclability.
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Affiliation(s)
- Xiaoxian Lu
- National Key Laboratory of Biobased Transportation Fuel TechnologyInternational Research Center for X PolymersDepartment of Polymer Science and EngineeringZhejiang UniversityHangzhou310027China
| | - Xun Zhang
- National Key Laboratory of Biobased Transportation Fuel TechnologyInternational Research Center for X PolymersDepartment of Polymer Science and EngineeringZhejiang UniversityHangzhou310027China
| | - Chengjian Zhang
- National Key Laboratory of Biobased Transportation Fuel TechnologyInternational Research Center for X PolymersDepartment of Polymer Science and EngineeringZhejiang UniversityHangzhou310027China
| | - Xinghong Zhang
- National Key Laboratory of Biobased Transportation Fuel TechnologyInternational Research Center for X PolymersDepartment of Polymer Science and EngineeringZhejiang UniversityHangzhou310027China
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5
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Xie X, Huo Z, Jang E, Tong R. Recent advances in enantioselective ring-opening polymerization and copolymerization. Commun Chem 2023; 6:202. [PMID: 37775528 PMCID: PMC10541874 DOI: 10.1038/s42004-023-01007-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 09/15/2023] [Indexed: 10/01/2023] Open
Abstract
Precisely controlling macromolecular stereochemistry and sequences is a powerful strategy for manipulating polymer properties. Controlled synthetic routes to prepare degradable polyester, polycarbonate, and polyether are of recent interest due to the need for sustainable materials as alternatives to petrochemical-based polyolefins. Enantioselective ring-opening polymerization and ring-opening copolymerization of racemic monomers offer access to stereoregular polymers, specifically enantiopure polymers that form stereocomplexes with improved physicochemical and mechanical properties. Here, we highlight the state-of-the-art of this polymerization chemistry that can produce microstructure-defined polymers. In particular, the structures and performances of various homogeneous enantioselective catalysts are presented. Trends and future challenges of such chemistry are discussed.
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Affiliation(s)
- Xiaoyu Xie
- Department of Chemical Engineering, Virginia Polytechnic Institute and State University, 635 Prices Fork Road, Blacksburg, Virginia, 24061, USA
| | - Ziyu Huo
- Department of Chemical Engineering, Virginia Polytechnic Institute and State University, 635 Prices Fork Road, Blacksburg, Virginia, 24061, USA
| | - Eungyo Jang
- Department of Chemical Engineering, Virginia Polytechnic Institute and State University, 635 Prices Fork Road, Blacksburg, Virginia, 24061, USA
| | - Rong Tong
- Department of Chemical Engineering, Virginia Polytechnic Institute and State University, 635 Prices Fork Road, Blacksburg, Virginia, 24061, USA.
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6
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Fornacon-Wood C, Stühler MR, Gallizioli C, Manjunatha BR, Wachtendorf V, Schartel B, Plajer AJ. Precise construction of weather-sensitive poly(ester- alt-thioesters) from phthalic thioanhydride and oxetane. Chem Commun (Camb) 2023; 59:11353-11356. [PMID: 37655470 DOI: 10.1039/d3cc03315e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
We report the selective ring opening copolymerisation (ROCOP) of oxetane and phthalic thioanhydride by a heterobimetallic Cr(III)K catalyst precisely yielding semi-crystalline alternating poly(ester-alt-thioesters) which show improved degradability due to the thioester links in the polymer backbone.
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Affiliation(s)
- Christoph Fornacon-Wood
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, Berlin 14195, Germany.
| | - Merlin R Stühler
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, Berlin 14195, Germany.
| | - Cesare Gallizioli
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, Berlin 14195, Germany.
| | - Bhargav R Manjunatha
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, Berlin 14195, Germany.
| | - Volker Wachtendorf
- Bundesanstalt für Materialforschung und -Prüfung (BAM), Unter den Eichen 87, Berlin 12205, Germany
| | - Bernhard Schartel
- Bundesanstalt für Materialforschung und -Prüfung (BAM), Unter den Eichen 87, Berlin 12205, Germany
| | - Alex J Plajer
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, Berlin 14195, Germany.
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7
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Fornacon-Wood C, Manjunatha BR, Stühler MR, Gallizioli C, Müller C, Pröhm P, Plajer AJ. Precise cooperative sulfur placement leads to semi-crystallinity and selective depolymerisability in CS 2/oxetane copolymers. Nat Commun 2023; 14:4525. [PMID: 37500621 PMCID: PMC10374558 DOI: 10.1038/s41467-023-39951-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 07/05/2023] [Indexed: 07/29/2023] Open
Abstract
CS2 promises easy access to degradable sulfur-rich polymers and insights into how main-group derivatisation affects polymer formation and properties, though its ring-opening copolymerisation is plagued by low linkage selectivity and small-molecule by-products. We demonstrate that a cooperative Cr(III)/K catalyst selectively delivers poly(dithiocarbonates) from CS2 and oxetanes while state-of-the-art strategies produce linkage scrambled polymers and heterocyclic by-products. The formal introduction of sulfur centres into the parent polycarbonates results in a net shift of the polymerisation equilibrium towards, and therefore facilitating, depolymerisation. During copolymerisation however, the catalyst enables near quantitative generation of the metastable polymers in high sequence selectivity by limiting the lifetime of alkoxide intermediates. Furthermore, linkage selectivity is key to obtain semi-crystalline materials that can be moulded into self-standing objects as well as to enable chemoselective depolymerisation into cyclic dithiocarbonates which can themselves serve as monomers in ring-opening polymerisation. Our report demonstrates the potential of cooperative catalysis to produce previously inaccessible main-group rich materials with beneficial chemical and physical properties.
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Affiliation(s)
- Christoph Fornacon-Wood
- Intitut für Chemie und Biochemie., Freie Universität Berlin, Fabeckstraße 34-36, 14195, Berlin, Germany
| | - Bhargav R Manjunatha
- Intitut für Chemie und Biochemie., Freie Universität Berlin, Fabeckstraße 34-36, 14195, Berlin, Germany
| | - Merlin R Stühler
- Intitut für Chemie und Biochemie., Freie Universität Berlin, Fabeckstraße 34-36, 14195, Berlin, Germany
| | - Cesare Gallizioli
- Intitut für Chemie und Biochemie., Freie Universität Berlin, Fabeckstraße 34-36, 14195, Berlin, Germany
| | - Carsten Müller
- Intitut für Chemie und Biochemie., Freie Universität Berlin, Fabeckstraße 34-36, 14195, Berlin, Germany
| | - Patrick Pröhm
- Intitut für Chemie und Biochemie., Freie Universität Berlin, Fabeckstraße 34-36, 14195, Berlin, Germany
| | - Alex J Plajer
- Intitut für Chemie und Biochemie., Freie Universität Berlin, Fabeckstraße 34-36, 14195, Berlin, Germany.
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8
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Xia Y, Yuan P, Zhang Y, Sun Y, Hong M. Converting Non-strained γ-Valerolactone and Derivatives into Sustainable Polythioesters via Isomerization-driven Cationic Ring-Opening Polymerization of Thionolactone Intermediate. Angew Chem Int Ed Engl 2023; 62:e202217812. [PMID: 36757807 DOI: 10.1002/anie.202217812] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/17/2023] [Accepted: 02/09/2023] [Indexed: 02/10/2023]
Abstract
This contribution reports the efficient conversion of γ-valerolactone and its derivatives, abundant but unexplored renewable feedstocks, into sustainable and degradable polythioesters via the establishment of the first isomerization-driven ring-opening polymerizations (IROPs) of corresponding thionolactone intermediates. The key to this success relies on the development of a new simple and robust [Et3 O]+ [B(C6 F5 )4 ]- cationic initiator which possesses high activity, exclusive selectivity, living nature, and broad scope of thionolactones. A complete inversion of configuration during IROP of enantiopure γ-thionovalerolactone is also disclosed, affording isotactic semicrystalline polythioesters (Tm =87.0 °C) with mechanical property compared well to the representative commodity polyolefins. The formation of a highly crystalline supramolecular stereocomplex with enhanced thermal property (Tm =117.6 °C) has also been revealed.
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Affiliation(s)
- Yongliang Xia
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Pengjun Yuan
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yanping 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
| | - Yangyang Sun
- 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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9
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Wang Y, Zhu Y, Lv W, Wang X, Tao Y. Tough while Recyclable Plastics Enabled by Monothiodilactone Monomers. J Am Chem Soc 2023; 145:1877-1885. [PMID: 36594572 DOI: 10.1021/jacs.2c11502] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The current scale of plastics production and the attendant waste disposal issues represent an underexplored opportunity for chemically recyclable polymers. Typical recyclable polymers are subject to the trade-off between the monomer's polymerizability and the polymer's depolymerizability as well as insufficient performance for practical applications. Herein, we demonstrate that a single atom oxygen-by-sulfur substitution of relatively highly strained dilactone is an effective and robust strategy for converting the "non-recyclable" polyester into a chemically recyclable polymer by lowering the ring strain energy in the monomer (from 16.0 kcal mol-1 in dilactone to 9.1 kcal mol-1 in monothiodilactone). These monothio-modification monomers enable both high/selective polymerizability and recyclability, otherwise conflicting features in a typical monomer, as evidenced by regioselective ring-opening, minimal transthioesterifications, and quantitative recovery of the pristine monomer. Computational and experimental studies demonstrate that an n→π* interaction between the adjacent ester and thioester in the polymer backbone has been implicated in the high selectivity for propagation over transthioesterification. The resulting polymer demonstrates high performance with its mechanical properties being comparable to some commodity polyolefins. Thio-modification is a powerful strategy for enabling conversion of six-membered dilactones into chemically recyclable and tough thermoplastics that exhibit promise as next-generation sustainable polymers.
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Affiliation(s)
- Yanchao Wang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022, People's Republic of China
| | - Yinuo Zhu
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022, People's Republic of China
| | - Wenxiu Lv
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022, People's Republic of China
| | - Xianhong Wang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022, People's Republic of China
| | - Youhua Tao
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022, People's Republic of China
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10
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Zhang Z, Shi C, Scoti M, Tang X, Chen EYX. Alternating Isotactic Polyhydroxyalkanoates via Site- and Stereoselective Polymerization of Unsymmetrical Diolides. J Am Chem Soc 2022; 144:20016-20024. [PMID: 36256876 DOI: 10.1021/jacs.2c08791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Naturally produced, biodegradable polyhydroxyalkanoates (PHAs) promise more sustainable alternatives to nonrenewable/degradable plastics, but biological PHA's stereomicrostructures are strictly confined to isotactic (R)-polymers or copolymers of random sequences. Chemical synthesis via catalyzed ring-opening polymerization (ROP) of cyclic (di)esters offers expedient access to diverse PHA microstructures, including those with defined comonomer sequences and tacticities. However, the synthesis of alternating isotactic PHAs has not been achieved by the existing methodologies. Here, we report the design of unsymmetrically disubstituted eight-membered diolides (rac-8DLR1-R2) and their site- and stereoselective ROP with discrete chiral catalysts, enabling the synthesis of alternating isotactic PHAs, poly(3-hydroxybutyrate-alt-3-hydroxyvalerate) (alt-P3HBV) and poly(3-hydroxybutyrate-alt-3-hydroxyheptanoate) (alt-P3HBHp), with high to quantitative (>99%) alternation and isotacticity and Mn up to 113 kDa and Đ = 1.01. Physical properties of such PHAs are substantially determined by the degree of backbone sequence alternation and tacticity, ranging from amorphous to semi-crystalline materials. The alt-P3HBV shows significantly improved mechanical performance relative to the constituent homopolymers. Intriguingly, enantiomeric (R)-alt-P3HBV and (S)-alt-P3HBV, synthesized by kinetically resolved ROP of rac-8DLMe-Et, form a stereocomplex with a significantly enhanced Tm (by 53 °C), while the enantiomeric homopolymers do not form a stereocomplex.
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Affiliation(s)
- Zhen Zhang
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Changxia Shi
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Miriam Scoti
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States.,Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Monte S. Angelo, Via Cintia, Napoli 80126, Italy
| | - Xiaoyan Tang
- 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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11
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Zaky MS, Wirotius AL, Coulembier O, Guichard G, Taton D. Reaching High Stereoselectivity and Activity in Organocatalyzed Ring-Opening Polymerization of Racemic Lactide by the Combined Use of a Chiral (Thio)Urea and a N-Heterocyclic Carbene. ACS Macro Lett 2022; 11:1148-1155. [PMID: 36067070 DOI: 10.1021/acsmacrolett.2c00457] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Stereochemical control during polymerization is a key strategy of polymer chemistry to achieve semicrystalline engineered plastics. The stereoselective ring-opening polymerization (ROP) of racemic lactide (rac-LA), which can lead to highly isotactic polylactide (PLA), is one of the emblematic examples in this area. Surprisingly, stereoselective ROP of rac-LA employing chiral organocatalysts has been under-leveraged. Here we show that a commercially available chiral thiourea (TU1), or its urea homologue (U1), can be used in conjunction with an appropriately selected N-heterocyclic carbene (NHC) to trigger the stereoselective ROP of rac-LA at room temperature in toluene. Both a high organic catalysis activity (>90% monomer conversion in 5-9 h) and a high stereoselectivity (probability of formation of meso dyads, Pm, in the range 0.82-0.93) can be achieved by thus pairing a NHC and a chiral amino(thio)urea. The less sterically hindered and the more basic NHC, that is, a NHC bearing tert-butyl substituents (NHCtBu), provides the highest stereoselectivity when employed in conjunction with the chiral TU1 or U1. This asymmetric organic catalysis strategy, as applied here in polymerization chemistry, further expands the field of possibilities to achieve bioplastics with adapted thermomechanical properties.
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Affiliation(s)
- Mohamed Samir Zaky
- Laboratoire de Chimie des Polymères Organiques (LCPO), UMR 5629, Université de Bordeaux, INP-ENSCBP, 16 av, Pey Berland, 33607 PESSAC Cedex France
| | - Anne-Laure Wirotius
- Laboratoire de Chimie des Polymères Organiques (LCPO), UMR 5629, Université de Bordeaux, INP-ENSCBP, 16 av, Pey Berland, 33607 PESSAC Cedex France
| | - Olivier Coulembier
- Center of Innovation and Research in Materials and Polymers (CIRMAP), Laboratory of Polymeric and Composite Materials, University of Mons, Mons B-7000, Belgium
| | - Gilles Guichard
- Univ. Bordeaux, CNRS, CBMN, UMR 5248, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, F-33607 Pessac, France
| | - Daniel Taton
- Laboratoire de Chimie des Polymères Organiques (LCPO), UMR 5629, Université de Bordeaux, INP-ENSCBP, 16 av, Pey Berland, 33607 PESSAC Cedex France
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12
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Li H, Guillaume SM, Carpentier J. Polythioesters Prepared by Ring-Opening Polymerization of Cyclic Thioesters and Related Monomers. Chem Asian J 2022; 17:e202200641. [PMID: 35816010 PMCID: PMC9543045 DOI: 10.1002/asia.202200641] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/07/2022] [Indexed: 11/11/2022]
Abstract
Polyhydroxyalkanoates (PHAs) are biodegradable and biocompatible polyesters with a wide range of applications; in particular, they currently stand as promising alternatives to conventional polyolefin-based "plastics". The introduction of sulfur atoms within the PHAs backbone can endow the resulting polythioesters (PTEs) with differentiated, sometimes enhanced thermal, optical and mechanical properties, thereby widening their versatility and use. Hence, PTEs have been gaining increasing attention over the past half-decade. This review highlights recent advances towards the synthesis of well-defined PTEs by ring-opening polymerization (ROP) of cyclic thioesters - namely thiolactones - as well as of S-carboxyanhydrides and thionolactones; it also covers the ring-opening copolymerization (ROCOP) of cyclic thioanhydrides or thiolactones with epoxides or episulfides. Most of the ROP reactions described are of anionic type, mediated by inorganic, organic or organometallic initiators/catalysts, along with a few enzymatic reactions as well. Emphasis is placed on the reactivity of the thio monomers, in relation to their ring-size ranging from 4- to 5-, 6- and 7-membered cycles, the nature of the catalyst/initiating systems implemented and their efficiency in terms of activity and control over the PTE molar mass, dispersity, topology, and microstructure.
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Affiliation(s)
- Hui Li
- Univ RennesCNRSISCR-UMR 622635000RennesFrance
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