Visible-Light-Driven Aza-ortho-quinone Methide Generation for the Synthesis of Indoles in a Multicomponent Reaction

Abstract

A visible-light-driven radical-mediated strategy for the in situ generation of aza-ortho-quinone methides from 2-vinyl-substituted anilines and alkyl radical precursors is described. This process enables an efficient multicomponent reaction of 2-vinylanilines, halides, and sulfur ylides, and has a wide substrate scope and good functional group tolerance. Treatment of the cycloaddition products with a base leads to densely functionalized indoles in a single-flask operation.

Keywords: aza-ortho-quinone methides; indoles; photochemistry; radicals; sulfur ylides.