Palladium-Catalyzed Asymmetric Cycloadditions of Vinylcyclopropanes and in Situ Formed Unsaturated lmines: Construction of Structurally and Optically Enriched Spiroindolenines
Palladium-Catalyzed Asymmetric Cycloadditions of Vinylcyclopropanes and in Situ Formed Unsaturated lmines: Construction of Structurally and Optically Enriched Spiroindolenines
复制标题
DOI：
10.1021/ol503383x
复制
发表时间：
2015-01-02
期刊：
影响因子：
5.2
通讯作者：
Liu, Quan-Zhong
中科院分区：
文献类型：
--
作者：
Liu, Ze-Shui;Li, Wen-Ke;Liu, Quan-Zhong
本文报道了钯催化下芳基磺酰基吲哚原位生成的α，β-不饱和亚胺与乙烯基环丙烷的（3 + 2）环加成反应。该反应以高的非对映选择性进行，以高达74%的产率和高达97%ee提供光学富集的螺环戊烷-1，3’-吲哚啉，其含有全碳季中心和两个叔立体中心。该反应涉及从乙烯基环丙烷到原位形成的不饱和亚胺的两性离子π-烯丙基钯络合物的碳阴离子的第一共轭加成，随后是钯催化的吲哚的分子内C-3-烯丙基化。
A palladium-catalyzed (3 + 2) cycloaddition of vinyl cyclopropane and alpha,beta-unsaturated imines generated in situ from aryl sulfonyl indoles is reported. The reaction proceeds with high diastereoselectivity to provide the optically enriched spirocyclopentane-1,3'-indolenines in up to 74% yield and with up to 97% ee, which contains an all-carbon quaternary center and two tertiary stereocenters. The reaction involves a first conjugate addition of the carbon anion of zwitterionic pi-allylpalladium complex from vinyl cyclopropane to the in situ formed unsaturated imine followed by a palladium-catalyzed intramolecular C-3-allylation of indole.