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.