A General Platform for the Construction of Sulfonylated Heterocycles with Indoles as Catalysts via Visible-Light Photocatalysis

A general photocatalytic platform has been developed for the synthesis of sulfonyl-substituted heterocycles from alkenes/alkynes and alkyl sulfonyl chlorides by using indoles as catalysts. This platform relies on the radical cascade cyclization without metal and base involvement and can be carried out with water as the reaction solvent. Mechanistic studies have indicated that the in situ-generated indole oligomers are the photocatalysts for this reaction.