S -Aminodibenzo[ b ]thiophenium Salts as Precursors for the Photoredox-Catalyzed Generation of Sulfamoyl Radicals

S -Aminodibenzo[ b ]thiophenium salts, accessible from S -methoxydibenzo[ b ]thiophenium tetrafluoroborate and the parent amines, are introduced as alternative precursors for the in situ generation of sulfamoyl radicals. Irradiation of S -aminodibenzo[ b ]thiophenium salts and the solid SO 2 surrogate DABSO with visible light in the presence of the organic photoredox catalyst Eosin Y affords sulfamoyl radicals as versatile reactive intermediates for the synthesis of sulfonamides. The utilization of this approach is demonstrated in the three-component synthesis of β-ketosulfonamides.