Dual Semiconductor‐Photoredox/Halogen‐Bonding Organocatalyzed Cascade Sulfonylation/Cyclization of Alkynes and Alkenes with RSO2Cl

The first dual semiconductor‐photoredox/halogen‐bonding catalyzed cascade sulfonylation/cyclization of arene‐tethered alkynes/alkenes with RSO2Cl is reported. Mechanistic studies show that the system facilitates S─Cl bond cleavage via two distinct pathways: the semiconductor enables heterolytic cleavage via SET, while the sulfonylated arene promotes homolytic cleavage through EnT. Abstract The dual semiconductor‐photoredox/halogen‐bonding organocatalyzed cascade sulfonylation/cyclization of (hetero)arene‐tethered alkynes and alkenes with RSO2Cl 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 RSO2Cl to form a halogen‐bonding complex, which facilitates S─Cl bond cleavage under blue light irradiation. Specifically, the Sr3N2 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. The first dual semiconductor-photoredox/halogen-bonding catalyzed cascade sulfonylation/cyclization of arene-tethered alkynes/alkenes with RSO 2 Cl is reported. Mechanistic studies show that the system facilitates S─Cl bond cleavage via two distinct pathways: the semiconductor enables heterolytic cleavage via SET, while the sulfonylated arene promotes homolytic cleavage through EnT. 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. Advanced Science, EarlyView.