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.