Pincer iridium(Ⅲ)-catalyzed enantioselective C(sp3)-H functionalization via carbenoid C–H insertion of 3-diazooxindoles with 1,4-cyclohexadiene  

作　　者：Nan Li Xiaoyan Yang Yanyan Zhu Fang Wang Junfang Gong Maoping Song 

机构地区：[1]College of Chemistry,Green Catalysis Center,Zhengzhou University,Zhengzhou 450001,China

出　　处：《Chinese Chemical Letters》2022年第5期2437-2441,共5页中国化学快报（英文版）

基　　金：supported by a grant from the National Nat-ural Science Foundation of China(No.21472176).

摘　　要：The asymmetric carbenoid C–H insertion of 3-diazooxindoles into 1,4-cyclohexadiene has been accomplished in the presence of chiral bis(imidazoline) NCN pincer iridium(Ⅲ) complexes as the catalysts. With a catalyst loading of 0.5 mol%, the reactions proceeded smoothly at 0℃ to afford a variety of chiral 3-substituted oxindoles in good yields with moderate to excellent enantioselectivities(up to 99% ee). The protocol exhibits good functional group tolerance with respect to 3-diazooxindoles and is readily scaled up to 2 mmol scale without any loss in activity and enantioselectivity. Density functional theory(DFT)calculations have been performed to better understand the reaction mechanism and to explain the stereochemical outcome of the reactions.

关 键 词：Asymmetric catalysis C–H functionalization Pincer iridium(III)catalyst Carbenoid C–H insertion 3-Diazooxindole Chiral 3-substituted oxindole 

分 类 号：O621.251[理学—有机化学]