Highly active bifunctional salenTi(Ⅳ) catalysts for asymmetric cyanosilylation of aldehydes and TMSCN  

作　　者：Ye Qian Wen Wei Min Ren Xiao Bing Lu 

机构地区：[1]State Key Laboratory of Fine Chemicals, Dalian University of Technolog3 [2] Dalian 116024, China

出　　处：《Chinese Chemical Letters》2011年第11期1285-1288,共4页中国化学快报（英文版）

基　　金：support by a Foundation for the Author of National Excellent Doctoral Dissertation of China(No FANEDD,200759)

摘　　要：A novel enantiopure salen ligand bearing a diphenylphosphine oxide on the 3-position of one aromatic ring was synthesized and combined with Ti（Oi-Pr）_4 as a monometallic bifunctional catalyst for asymmetric cyanosilylation reaction of aldehydes with tnmethylsilyl cyanide（TMSCN）.The catalyst system exhibited excellent activity and moderate enantioselectivity.The addition of TMSCN to 4-nitrobenzaldehyde in the presence of 1 mol%catalyst loading could complete within 10 min at ambient temperature. An intramolecularly cooperative catalysis was observed in this system wherein the central metal Ti（Ⅳ） is suggested to play a role of Lewis acid to activate aldehydes while the appended diphenylphosphine oxide worked as Lewis base to activate TMSCN.A novel enantiopure salen ligand bearing a diphenylphosphine oxide on the 3-position of one aromatic ring was synthesized and combined with Ti（Oi-Pr）_4 as a monometallic bifunctional catalyst for asymmetric cyanosilylation reaction of aldehydes with tnmethylsilyl cyanide（TMSCN）.The catalyst system exhibited excellent activity and moderate enantioselectivity.The addition of TMSCN to 4-nitrobenzaldehyde in the presence of 1 mol%catalyst loading could complete within 10 min at ambient temperature. An intramolecularly cooperative catalysis was observed in this system wherein the central metal Ti（Ⅳ） is suggested to play a role of Lewis acid to activate aldehydes while the appended diphenylphosphine oxide worked as Lewis base to activate TMSCN.

关 键 词：Cyanohydnn Bifunctional catalyst SALEN TMSCN Diphenylphosphine oxide 

分 类 号：TQ223.24[化学工程—有机化工] TQ246.15