Photochemical aerobic sulfonylation–cyclization–selenylation to indole-fused medium-sized N-heterocycles in 2-Me-THF

Indole-fused medium-sized diazepinones are privileged structural motifs found in many high-value pharmaceuticals. To construct these challenging molecular skeletons, previous methods are mainly achieved by [5+2] annulation strategies with the aid of transition metal (Pd, Rh, Ru) catalyzed oxidative C–H coupling. Herein, we report a novel visible-light-induced sulfonylation–cyclization–selenylation reaction for the rapid construction of highly functionalized indole-fused medium-sized diazepinones with biomass feedstock 2-Me-THF as the medium. Based on the mechanism studied, an electrophilic radical sulfonylation–cyclization and subsequent aerobic electrophilic C-3 selenylation route is proposed.