Complications in the Castagnoli-Cushman reaction: An unusual course of reaction between cyclic anhydrides and sterically hindered indolenines
作者:Maria Chizhova、Dmitry Dar'in、Mikhail Krasavin
DOI:10.1016/j.tetlet.2017.07.077
日期:2017.8
Attempted reaction of indolenines (which represent rather sterically hindered cyclic imines) with a series of dicarboxylic acid anhydrides yielded no expected product, the Castagnoli-Cushman lactam. Instead, products presumably formed via N-acyliminium species trapping by a carboxylate anion. Among them, hydrolytically labile 2:2 adducts of an indolenine and a cyclic anhydride, containing a 16-membered
吲哚烯胺(代表空间上受阻的环状亚胺)与一系列二羧酸酐的尝试反应未产生预期的产物,Castagnoli-Cushman内酰胺。取而代之的是,推测是通过被羧酸根阴离子捕获的N-酰基亚胺类物质形成的产物。其中,含有16元环状核的吲哚和环酸酐的水解不稳定的2:2加合物特别令人着迷。该结果与最近报道的吲哚与高邻苯二甲酸酐的Castagnoli-Cushman反应成功相反,表明在反应过程中发生了机理转换。