Radical C(sp3)–S Coupling for the Synthesis of α-Amino Sulfides

A unique transition-metal-free radical thiolation of 2-azaallyl anions has been developed. Easily accessible thiosulfonates and 2-azaallyls undergo the tandem process of single-electron transfer and radical–radical coupling to construct C(sp3)–S bonds. This robust protocol enables a mild and chemoselective coupling between 2-azaallyl anions and thiosulfonates to access α-amino sulfides in 50–92% yields (25 examples). The scalability of this protocol was demonstrated by telescopic gram-scale experiments. Mechanistic studies provide significant evidence for this radical thiolation reaction.