Pd-Catalyzed Enantioselective Tandem C–C Bond Activation/Cacchi Reaction between Cyclobutanones and <i>o</i>-Ethynylanilines
作者:Wan-Chun Yang、Xiao-Bing Chen、Kun-Long Song、Bin Wu、Wan-Er Gan、Zhan-Jiang Zheng、Jian Cao、Li-Wen Xu
DOI:10.1021/acs.orglett.0c04297
日期:2021.2.19
A palladium-catalyzed asymmetric tandem C–C bond activation/Cacchi reaction between cyclobutanones and o-ethynylanilines was reported. The transient chiral σ-alkylpalladium species generated via enantioselective C(sp3)–C(sp2) bond activation of cyclobutanones promotes cyclization of o-ethynylanilines, leading to one-carbon-tethered chiral indanone-substituted indoles. Two C–C bonds and one C–N bond
据报道,环丁酮与邻乙炔基苯胺之间存在钯催化的不对称串联CC键活化/ Cacchi反应。通过环丁酮的对映选择性C(sp 3)–C(sp 2)键活化而产生的瞬时手性σ-烷基钯物质,促进了邻乙炔基苯胺的环化反应,从而导致一碳束缚的手性茚满酮取代的吲哚。伴随着全碳四元立体中心的形成,产生了两个C–C键和一个C–N键。此外,可以在2,3-二取代的吲哚部分中形成手性C 2-芳基轴,从而导致具有中心和轴向立体生成元素的茚满酮取代的吲哚。