Chemoselective N–H or C-2 Arylation of Indole-2-carboxamides: Controllable Synthesis of Indolo[1,2-<i>a</i>]quinoxalin-6-ones and 2,3′-Spirobi[indolin]-2′-ones
作者:Lingkai Kong、Yue Sun、Zhong Zheng、Rong Tang、Mengdan Wang、Yanzhong Li
DOI:10.1021/acs.orglett.8b02197
日期:2018.9.7
chemoselective N–H or C-2 arylation for the synthesis of indolo[1,2-a]quinoxalin-6-ones and 2,3′-spirobi[indolin]-2′-ones starting from indole-2-carboxamides were developed. When reactions were carried out using ZnI2 as catalyst and Ag2CO3 as oxidant, indolo[1,2-a]quinoxalin-6-ones were synthesized in up to 86% yields via intramolecular N–H/C–H coupling, whereas the dearomative cyclization reactions were realized
涉及化学选择性NH或C-2芳基化反应的新方法,从吲哚2开始合成吲哚并[1,2 - a ]喹喔啉-6-和2,3'-螺双[吲哚啉] -2'-。 -羧酰胺被开发出来。当使用ZnI 2作为催化剂和Ag 2 CO 3作为氧化剂进行反应时,通过分子内N–H / C–H偶联,吲哚[1,2 - a ]喹喔啉-6-一的合成产率高达86%,而脱芳香环化反应是在TfOH存在下实现的,通过C–H官能化或Fridel–Crafts烷基化反应导致吲哚的C-2芳基化,得到2,3'-spirbibi [indolin] -2'-ones。中等至极好的产量。