Photocatalyst-, metal- and additive-free regioselective radical cascade sulfonylation/cyclization of benzimidazole derivatives with sulfonyl chlorides induced by visible light

An environmentally friendly and practical protocol for the visible-light-triggered regioselective radical cascade sulfonylation/cyclization of unactivated alkenes towards the synthesis of polycyclic benzimidazoles containing the sulfone group has been developed.