A new method has been developed for constructing vicinal quaternary stereocenters with an oxindole–butanolide hybrid framework through asymmetric vinylogous addition of a siloxyfuran to an indol-2-one in the presence of a readily available N,N′-dioxide–Ni(OTf)2 complex catalyst. Various oxindole–lactones were obtained in up to 98% yield with >19:1 dr and 97% ee under mild reaction conditions. A possible
开发了一种新方法,通过在容易获得的N , N ' -二氧化物-Ni(OTf)存在下,将甲硅氧呋喃不对称插烯加成到吲哚-2-酮上,从而构建具有羟吲哚-丁内酯杂化骨架的邻位季立体中心2络合物催化剂。在温和的反应条件下,以 >19:1 dr 和 97% ee 获得了高达 98% 的收率和 97% ee 的各种羟吲哚内酯。提出了一种可能的过渡态模型来解释不对称感应的起源。