Visible Light‐Induced Three‐Component 1,2‐Acylarylation of Quinoxalin‐2(1 H )‐Ones with Styrenes and Oxime Esters

Visible light‐driven transformations offer an attractive strategy for sustainable synthesis by simplifying reaction systems while maintaining high efficiency. Herein, we report an exogenous photocatalyst‐free visible light‐induced three‐component 1,2‐acylarylation of quinoxalin‐2(1 H )‐ones with styrenes and acyl oxime esters under mild conditions. Exploiting the intrinsic photoactivity of quinoxalin‐2(1 H )‐ones, direct excitation under purple LED irradiation enables single electron transfer (SET) to acyl oxime esters, generating acyl radicals without the need for external photocatalysts. The resulting radicals undergo a sequential addition to alkenes and quinoxalin‐2(1 H )‐ones, affording structurally diverse C3‐functionalized products in moderate to good yields. The current three‐component coupling protocol exhibits broad substrate scope, tolerating a range of styrenes, quinoxalin‐2(1 H )‐ones, and benzoyl oxime esters. Mechanistic studies, including radical trapping experiments, fluorescence quenching, and UV–Vis analysis, support a SET‐driven radical relay pathway involving a photoexcited quinoxalin‐2(1 H )‐one. This operationally simple and modular approach highlights the dual role of quinoxalin‐2(1 H )‐ones as both substrate and photoactive species, expanding the scope of exogenous photocatalyst‐free multicomponent radical transformations.