Copper(II)-catalyzed synthesis of ­indoloquinoxalin-6-ones through oxidative mannich reaction

Abstract

A Cu‐catalyzed synthesis of indoloquinoxalin‐6‐one has been developed that starts from o‐indolyl‐N,N‐dialkylamines through sp³ C–H bond oxidation α to the nitrogen atom with di‐tert‐butyl peroxide as oxidant. Other heterocycles, such as pyrrole, imidazole and benzimidazole derivatives also reacted successfully to give their respective fused quinoxalin‐6‐one derivatives. In this process, one of the methyl groups is transformed into a carbonyl group.