Lewis Pair Catalyzed Regioselective Polymerization of (E,E)-Alkyl Sorbates for the Synthesis of (AB)n Sequenced Polymers

Wuchao Zhao; Fukuan Li; Chengkai Li; Jianghua He; Yuetao Zhang; Changle Chen

doi:10.1002/anie.202111336

Lewis Pair Catalyzed Regioselective Polymerization of (E,E)-Alkyl Sorbates for the Synthesis of (AB)_n Sequenced Polymers

Angew Chem Int Ed Engl. 2021 Nov 2;60(45):24306-24311. doi: 10.1002/anie.202111336. Epub 2021 Oct 5.

Authors

Wuchao Zhao¹, Fukuan Li¹, Chengkai Li², Jianghua He¹, Yuetao Zhang¹, Changle Chen²

Affiliations

¹ State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin, 130012, P. R. China.
² 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.

PMID: 34510679
DOI: 10.1002/anie.202111336

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 (M_w 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).

Keywords: (AB)n sequenced copolymers; Lewis pairs; functional polypropylene; polymerization; post-polymerization functionalization.

Abstract

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