Photoredox-Catalyzed Three-Component Assembly of Primary Aryl Sulfonamides Using (NH₄)₂CO₃: Late-Stage Drug Sulfonamidation

Primary aryl sulfonamides feature prominently in medicinal chemistry and organic synthesis. Herein, a metal-free photoredox-catalyzed three-component assembly of primary aryl sulfonamides via an aryl sulfonyl ammonium trifluoromethanesulfonate intermediate has been described. A variety of structurally diverse primary aryl sulfonamides were synthesized rapidly from dibenzothiophenium (DBT) salts under simple and mild conditions using (NH₄)₂CO₃ as the nucleophile. Notably, this methodology can be employed as an efficient and sustainable approach for late-stage drug sulfonamidation. Broad functional group tolerance is a feature of this methodology. Moreover, the method was applied to the total synthesis of sulpiride to showcase its synthetic utility.