A radical-mediated multicomponent cascade reaction for the synthesis of azide-biindole derivatives

Abstract

A radical-mediated, one-pot, multicomponent cascade reaction was developed for the synthesis of azide-biindole derivatives. Mechanistic studies demonstrated that the nitrogen-centred free radical was formed by the reaction of heterocyclic N–H with Cu^II and PIFA and initiated the cascade reaction with indole to obtain the biindole intermediate. The biindole intermediate then reacted with sodium azide in the presence of Cu^II catalyst and PIFA to form the final products. This methodology may be useful for constructing other azido heterocycles.