Abstract The dual semiconductor‐photoredox/halogen‐bonding organocatalyzed cascade sulfonylation/cyclization of (hetero)arene‐tethered alkynes and alkenes with RSO 2 Cl is first developed. This method proceeds efficiently under mild reaction conditions, delivering a variety of sulfonylated fused‐(hetero)arenes with good functional group compatibility. Mechanistic investigations reveals that XantPhos interacts with RSO 2 Cl to form a halogen‐bonding complex, which facilitates S─Cl bond cleavage under blue light irradiation. Specifically, the Sr 3 N 2 semiconductor catalyst promotes heterolytic S─Cl bond cleavage through a SET process, generating a sulfonyl radical and chloride ion. In contrast, the sulfonylated fused‐(hetero)arene facilitates homolytic S─Cl bond cleavage via an EnT pathway, proudcing a sulfonyl radical.
Wang et al. (2025) studied this question.