Carbon–Carbon Bond Formation by Reaction of Rhodium Azavinylcarbenes with Secondary Amides: Access to Indigo Analogues from Isatins

A novel protocol
for the synthesis of unsymmetrical indigo-like
(E)-α-amino enaminones by rhodium-catalyzed
transformations of isatins with 1-tosyl-1,2,3-triazoles has been developed.
A plausible reaction mechanism is proposed to account for the formation
of structurally important unsymmetrical indigo analogues, which represents
a new strategy for C–C bond formation based on the transformations
of secondary amides and rhodium azavinylcarbenes.

本研究开发了一种全新的合成方法，可通过铑催化靛红（isatins）与1-对甲苯磺酰基-1,2,3-三氮唑（1-tosyl-1,2,3-triazoles）的转化反应，合成不对称类靛蓝型(E)-α-氨基烯胺酮。本研究同时提出了合理的反应机理，用以阐释具有重要结构价值的不对称靛蓝类似物的生成过程；该策略基于二级酰胺与铑氮杂乙烯卡宾（rhodium azavinylcarbenes）的转化反应，为C–C键构建提供了全新的研究路径。