Iron-Mediated Desulfonylative Cross-Electrophile Couplings of Heteroaryl Sulfones with Thiosulfonates for Efficient Synthesis of Heteroaryl Sulfides

A desulfonylative thiolation between heteroaryl sulfones and thiosulfonates for the efficient synthesis of heteroaryl sulfides was developed. The cross-electrophile couplings proceeded effectively via old C–SO₂ bond cleavage and new C–S bond formation in the presence of cheapest and widely available iron powder as mediator under transition metal catalyst-free conditions, leading to a wide array of heteroaryl sulfides derived from benzo[d]thiazole, benzo[d]oxazole, thiazole, 1,3,4-thiadiazole, and 1H-tetrazole in modest to excellent yields. In addition, the reaction exhibited good functional group compatibility, and the protocol could also be applicable to the use of selenosulfonate as substrate and be subjected to scale-up synthesis with equal ease. Notably, unreacted iron powder could be readily recovered after reaction by resorting to the attracting property of magnetic stir bar to iron.