DMSO/SOCl2-mediated C(sp2)–H amination: switchable synthesis of 3-unsubstituted indole and 3-methylthioindole derivatives

Abstract

The reaction of 2-alkenylanilines with SOCl₂ in DMSO was found to selectively afford 3-unsubstituted indoles and 3-methylthioindoles. This switchable approach was found to be temperature-dependent: at room temperature, the reaction afforded 3-unsubstituted indoles through intramolecular cyclization and elimination; while at higher temperature, the reaction gave 3-methylthioindoles via further electrophilic methylthiolation.