Phosphorothiosulfonates: new radical phosphorothiolation reagents for photocatalytic cyclization of alkenes/alkynes

We report the first synthesis of phosphorothiosulfonates as competent radical –S–P(O)(OR) 2 precursors. Under mild photoredox conditions, these reagents enable metal-, oxidant-free phosphorothiolation/cyclization of diverse alkenes and alkynes.