Asymmetric catalytic alkylation of vinyl azides with 3-bromo oxindoles: water-assisted chemo-and enantiocontrol  

作　　者：Ziwei Zhong Lichao Ning Yican Lu Jiuqi Tan Lili Lin Xiaoming Feng 

机构地区：[1]Key Laboratory of Green Chemistry&Technology,Ministry of Education,College of Chemistry,Sichuan University,Chengdu 610064,China

出　　处：《Science China Chemistry》2023年第3期799-807,共9页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(21871188,21921002);the Sichuan Science and Technology Program(2021YJ0561);the Sichuan University(2020SCUNL204)。

摘　　要：A highly chemo-and enantioselective alkylation of vinyl azides with 3-bromo-3-substituted oxindoles was achieved through a chiral N,N′-dioxide/Ni(OTf)2-mediated conjugate addition/water addition/elimination tandem process. Water was critical to the chemo-and enantioselectivity. The hydrated Na3PO4 acted as both a base and a reservoir to regulate the amount of water in solution. A wide range of enantioenriched oxindoles having α-carbonyl-substituted all-carbon quaternary stereocenters were achieved in good yields and good ee values(51 examples, up to 90% yield, 97% ee). Easy transformations of products to analogues of(+)-physovenine and(+)-desoxyeseroline enhanced the synthetic value. Mechanistic studies including control experiments, kinetic studies, and density functional theory(DFT) calculations, enabled a proposition of a possible catalytic cycle along with transition states to elucidate the reaction process and chiral induction.

关 键 词：asymmetric catalysis water assistance tandem reaction vinyl azide ketone surrogate 

分 类 号：O621.251[理学—有机化学]