Department of Polymer Science and Engineering, MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Zhejiang University, Hangzhou, 310027, China.
Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA.
Angew Chem Int Ed Engl. 2017 May 15;56(21):5774-5779. doi: 10.1002/anie.201701780. Epub 2017 Apr 26.
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 ). 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 at ambient temperature.
本文描述了由路易斯碱（脒、胍或季铵盐）和路易斯酸（三乙基硼烷）组成的无金属路易斯对催化剂，用于催化羰基硫（COS）与环氧化物共聚，制备完美交替、区域选择性的共聚物。成功获得了具有超过 99%的头-尾含量和高分子量（高达 92.5kgmol）的聚（单硫碳酸酯）的无色、高透明共聚物。在大多数情况下，会生成无规硫碳酸酯和碳酸酯单元的氧-硫交换反应（O/S ER）被有效抑制。这些路易斯对催化过程的转化率频率（TOF）高达 119h，在环境温度下进行。
