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Record Productivity and Unprecedented Molecular Weight for Ring‐Opening Copolymerization of Epoxides and Cyclic Anhydrides Enabled by Organoboron Catalysts
Author(s) -
Xie Rui,
Zhang YaoYao,
Yang GuanWen,
Zhu XiaoFeng,
Li Bo,
Wu GuangPeng
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202104981
Subject(s) - phthalic anhydride , polyester , catalysis , cyclohexane , dispersity , chemistry , polymer chemistry , copolymer , cyclohexene oxide , ring (chemistry) , epoxide , organic chemistry , polymer
Producing polyesters with high molecular weight (M n ) through ring‐opening copolymerization (ROCOP) of epoxides with cyclic anhydrides remains a major challenge. Herein, we communicate a metal‐free, highly active, and high thermoresistance system for the ROCOP of epoxides with cyclic anhydrides to prepare polyesters (13 examples). The organoboron catalysts can endure a reaction temperature as high as 180 °C for the ROCOP of cyclohexane oxide (CHO) with phthalic anhydride (PA) without the observation of any side reactions. The average M n of the produced poly(CHO‐alt‐PA) climbed to 94.5 kDa with low polydispersity (Ð=1.19). Furthermore, an unprecedented turnover number of 9900, equivalent to an efficiency of 7.4 kg of polyester/g of catalyst, was achieved at a feed ratio of CHO/PA/catalyst=20000:10000:1 at 150 °C. Kinetic studies, crystal structure analysis, 11 B NMR spectra, and DFT calculations provided mechanistic justification for the effectiveness of the catalyst system.