A self‐photocatalyzed sulfonylation/cyclization of quinazolinones containing unactivated alkenes with various sulfonyl chlorides was developed. The protocol provides access to sulfonyl radicals via energy transfer from the quinazolinone skeleton to the sulfonyl chloride. Notably, the transformations proceeded without any external photocatalysts, additives, or oxidants, providing an alternative method for fabricating sulfonylated compounds.

Herein, an environmental and practical protocol for the visible-light-triggered regioselective radical cascade sulfonylation/cyclization of unactivated alkenes towards synthesis of polycyclic benzimidazoles containing sulfone group has been developed. Notably, the control...