Sulfonamide formation from sodium sulfinates and amines or ammonia under metal-free conditions at ambient temperature

A novel, practical and highly efficient method for the construction of a variety of sulfonamides mediated by I-2 was demonstrated. The reaction proceeds readily at room temperature using a variety of sodium sulfinates and amines or ammonia in water in a metal-, base-, ligand-, or additive- free protocol. Primary, secondary and tertiary sulfonamides were obtained in good to excellent yields with a broad range of functional group tolerability.