Divergent synthesis of 6H-isoindolo[2,1-a]indol-6-ones and indenoindolones: an investigation of Pd-catalyzed isocyanide insertion
摘要:
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.
6H-isoindolo[2,1-α]indol-6-ones were developed. In the first protocol, 6H-isoindolo[2,1-α]indol-6-ones were prepared from 2-(2-iodophenyl)-1H-indoles viapalladium-catalyzed intramolecular aminocarbonylation. The second involves intermolecular carbonylation of indoles with iodobenzenes followed by intramolecular cross-dehydrogenative-coupling.
Pd-Catalyzed Cyclocarbonylation of 2-(2-Bromoaryl)indoles with CO as a C1 Source: Selective Access to 6 <i>H</i>-Isoindolo[2,1-<i>a</i>]indol-6-ones and Indeno[1,2-<i>b</i>]indol-10(5 <i>H</i>)-ones
作者:Shenghai Guo、Li Tao、Fang Wang、Xuesen Fan
DOI:10.1002/asia.201601067
日期:2016.11.7
A highly efficient and regioselectivesyntheticroute to 6 H‐isoindolo[2,1‐a]indol‐6‐ones and indeno[1,2‐b]indol‐10(5 H)‐ones through the Pd‐catalyzed cyclocarbonylation of 2‐(2‐bromoaryl)indoles under atmospheric CO pressure has been achieved. Notably, the regioselectivity of the reaction was exclusively dependent on the structural characteristics of the indole substrates. With N‐unsubstituted indoles
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。