<i>N</i>-Alkylation-Initiated Redox-Neutral [5 + 2] Annulation of 3-Alkylindoles with <i>o</i>-Aminobenzaldehydes: Access to Indole-1,2-Fused 1,4-Benzodiazepines
作者:Shuai Wang、Yao-Bin Shen、Long-Fei Li、Bin Qiu、Liping Yu、Qing Liu、Jian Xiao
DOI:10.1021/acs.orglett.9b03011
日期:2019.11.15
[5 + 2] annulation of 3-alkylindoles with o-aminobenzaldehydes via a cascade N-alkylation/dehydration/[1,5]-hydride transfer/Friedel–Crafts alkylation sequence. A series of indole-1,2-fused 1,4-benzodiazepines are facilely constructed in moderate to good yields in one step. This protocol features excellent regioselectivity, metal-free conditions, high step economy, and wide substrate scope.
本文描述的是通过级联N-烷基化/脱水/ [1,5]-氢化物转移/ Friedel-Crafts烷基化序列,前所未有的N-烷基化引发的3-烷基吲哚与邻氨基苯甲醛的氧化还原中性[5 + 2]环化反应。一步一步即可轻松构建一系列吲哚1,2-稠合的1,4-苯并二氮杂ze。该协议具有出色的区域选择性,无金属条件,高步骤经济性和广泛的底物范围。