Highly regio-and stereo-selective copolymerization of CO_2 with racemic propylene oxide catalyzed by unsymmetrical (S,S,S)-salenCo(Ⅲ) complexes  

作　　者：REN WeiMin,ZHANG WenZhen & LU XiaoBing State Key Laboratory of Fine Chemicals Dalian University of Technology,Dalian 116012,China 

出　　处：《Science China Chemistry》2010年第8期1646-1652,共7页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (20634040);National Basic Research Program of China (973 Program) (2009CB825300);the Outstanding Young Scientist Foundation of the National Natural Science Foundation of China (20625414)

摘　　要：A novel unsymmetrical (S,S,S)-salen ligand bearing a derived chiral-BINOL was synthesized by the reaction of the condensation product of (1S,2S)-1,2-diaminocyclohexane mono(hydrogen chloride) with 3-adamanyl-5-tert-butyl-2-hydroxybenzalde-hyde and 3-formoyl-2-hydroxy-2'-alkyloxy-1,1'-binaphthyl,which originated from (S)-1,1'-bi-2-naphthol via a four-step reaction.The cobalt complexes of this ligand,in conjunction with a nucleophilic cocatalyst,exhibited excellent activity in catalyzing asymmetric,regio-and stereo-selective copolymerization of CO2 and racemic propylene oxide.The highest record of kinetic resolution coefficient (Krel) was obtained with the use of binary catalyst system consisting of (S,S,S)-salenCo(III) complex 1c and bulky bis(triphenylphosphine)-iminium chloride (PPNCl).The resulting poly(propylene carbonate)s have more than 99% carbonate linkages and more than 98% head-to-tail content.A novel unsymmetrical (S,S,S)-salen ligand bearing a derived chiral-BINOL was synthesized by the reaction of the condensation product of (1S,2S)-1,2-diaminocyclohexane mono(hydrogen chloride) with 3-adamanyl-5-tert-butyl-2-hydroxybenzalde-hyde and 3-formoyl-2-hydroxy-2’-alkyloxy-1,1’-binaphthyl,which originated from (S)-1,1’-bi-2-naphthol via a four-step reaction.The cobalt complexes of this ligand,in conjunction with a nucleophilic cocatalyst,exhibited excellent activity in catalyzing asymmetric,regio-and stereo-selective copolymerization of CO2 and racemic propylene oxide.The highest record of kinetic resolution coefficient (Krel) was obtained with the use of binary catalyst system consisting of (S,S,S)-salenCo(III) complex 1c and bulky bis(triphenylphosphine)-iminium chloride (PPNCl).The resulting poly(propylene carbonate)s have more than 99% carbonate linkages and more than 98% head-to-tail content.

关 键 词：carbon dioxide PROPYLENE oxide POLYCARBONATE STEREOCHEMISTRY asymmetric catalysis polymerization kinetic resolution 

分 类 号：O631.5[理学—高分子化学]