Enantioselective Resolution Copolymerization of Racemic 2,3-Disubstituted cis-Epoxides with CO_(2) Mediated by Binuclear Cobalt(Ⅲ)Catalyst  

作　　者：Yan-Lan Liu Guang-Hui He Ye Liu Xiao-Bing Lu 

机构地区：[1]State Key Laboratory of Fine Chemicals,Dalian University of Technology,Dalian,Liaoning 116024,China

出　　处：《Chinese Journal of Chemistry》2021年第9期2386-2390,共5页中国化学（英文版）

摘　　要：Enan tioselective resoluti on copolymerization of racemic internal epoxides with carb on dioxide(CO_(2))is a challe nging issue because of their poor reactivity and complicated regio/stereoselectivity.Herein,we describe the first enantioselective resolution copolymeriza-tion of racemic aromatic 2,3-disubstituted c/s-epoxides and CO_(2) using enantiopure dinuclear cobalt(lll)complexes as catalyst under mild conditions,affordi ng the corresp on ding polycarbonates with completely alter nating structure and good enantioselectivity in the range of 70% to 97%ee.The isotactic polycarb on ate from/3-methylstyre ne oxide is a typical semicrystalli ne material,possessi ng a melting point of 241℃;while other isotactic-enriched copolymers from 2,3-disubstituted c/s-epoxides bearing a substitute group on the aromatic ring are amorphous,having glass transition temperatures between 86℃ and 124℃.Interestingly,the copolymer selectivity is correlated well with the Hammett substituent constant,and the highest polymer selectivity of 98%was found in the system using the epoxides bearing an electron-donating group on the benzene ring.

关 键 词：Asymmetric catalysis Internal c/s-epoxides Carbon dioxide fixation POLYMERIZATION Hammett constant 

分 类 号：O62[理学—有机化学]