通过2的Pd催化环羰基化反应制得6 H-异吲哚并[2,1- a ]吲哚-6-和茚并[1,2 - b ] indol-10(5 H)-1的高效且区域选择性的合成途径 在大气压CO压力下获得了(2-溴芳基)吲哚。值得注意的是,反应的区域选择性仅取决于吲哚底物的结构特征。以N-未取代的吲哚为起始原料,该反应获得了6 H-异吲哚并[2,1 - a ]吲哚-6-酮,收率为优良。另一方面,以N-取代的吲哚为底物,反应得到茚并[1,2 - b ] indol-10(5 H)-以高度区域选择性的方式进行。
本发明公开了一种茚[1,2‑ b ]吲哚‑10(5 H )‑酮类化合物的合成方法。本发明的技术方案要点为:以 N ‑取代‑2‑(2‑溴芳基)‑1 H ‑吲哚类化合物和CO为起始原料,以醋酸钯为催化剂,以DABCO为碱,以正丁基二(1‑金刚烷基)膦为配体,以二甲基亚砜或N‑甲基吡咯烷酮为溶剂,在反应容器中于120℃加热搅拌反应制得目标产物茚[1,2‑ b ]吲哚‑10(5 H )‑酮类化合物。本发明具有反应条件温和、起始原料简单易制备、底物适用范围广和操作简单等优点。
Divergent synthesis of 6H-isoindolo[2,1-a]indol-6-ones and indenoindolones: an investigation of Pd-catalyzed isocyanide insertion
A novel Pd-catalyzed intramolecular cyclization via tert-butyl isocyanide insertion from 2-(2-bromophenyl)-1H-indoles has been developed, which demonstrates the utility of isocyanides in C-N or C-C bond construction. Treatment of 2-(2-bromophenyl)-1H-indoles with tert-butyl isocyanide affords 6H-isoindolo[2,1-a]indol-6-ones with high efficiency. However, N-methyl or N-Boc protected 2-(2-bromophenyl)-1H-indoles gives indenoindolones in excellent yields under the same condition, which reveals that under the described situation, isocyanides insertion for the formation of C-N bonds is prior to that of C-C bonds. (C) 2014 Elsevier Ltd. All rights reserved.