Construction of gem-difluoroalkenyl indoles via photoinduced Fukuyama-type cyclization of isocyanides

Abstract

Efficient access to gem-difluoroalkenyl indoles through cyclization of trifluoromethyl alkene decorated phenyl isocyanides with alkyl (Me, 1o, 2o, 3o), sulfur and phosphonyl radical precursors has been developed. The imidoyl radical was rapidly trapped by the intramolecular CF3-substituted alkene and subsequent defluorination process offers a modular approach to diversified 3-gem-difluoroalkenyl indoles under mild reaction conditions with broad functional group tolerance.