Silver-Catalyzed Oxidative Cyclization of Propargylamide-Substituted Indoles: Synthesis of Phosphorated Indoloazepinones Derivatives

A silver-catalyzed oxidative cyclization of 2- or 3-propargylamide-substituted indoles to synthesize phosphorated indoloazepinone derivatives is described. This reaction displays a difunctionalizalion of alkynes with diphenylphosphine oxides to construct a seven-membered ring through a radical cyclization process. The indoloazepinones derivatives are common structural motifs found in many natural products and pharmaceuticals.