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Perfectly Alternating and Regioselective Copolymerization of Carbonyl Sulfide and Epoxides by Metal‐Free Lewis Pairs
Author(s) -
Yang JiaLiang,
Wu HaiLin,
Li Yang,
Zhang XingHong,
Darensbourg Donald J.
Publication year - 2017
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201701780
Subject(s) - lewis acids and bases , copolymer , frustrated lewis pair , polymer chemistry , sulfide , carbonyl sulfide , chemistry , borane , catalysis , regioselectivity , onium , sulfur , organic chemistry , polymer , ion
The preparation of perfectly alternating and regioslective copolymers derived from the copolymerization of carbonyl sulfide (COS) and epoxides by metal‐free Lewis pair catalysts composed of a Lewis base (amidine, guanidine, or quaternary onium salts) and a Lewis acid (triethyl borane) is described. Colorless and highly transparent copolymers of poly(monothiocarbonate) were successfully obtained with over 99 % tail‐to‐head content and high molecular weight (up to 92.5 kg mol −1 ). In most instances, oxygen–sulfur exchange reactions (O/S ERs), which would generate random thiocarbonate and carbonate units, were effectively suppressed. The turnover frequencies (TOF) of these Lewis pair catalyzed processes were as high as 119 h −1 at ambient temperature.