Metal-free visible-induced C(sp)-C(sp) coupling of quinoxalin-2()-ones oxidative cleavage of the C-N bond.

A C(sp)-C(sp) reaction between aromatic hydrazines and quinoxalines has been developed through a photocatalytic system. The protocol is established for C(sp)-N bond cleavage and direct C(sp)-H functionalization for the coupling of C(sp)-C(sp) photocatalysis under mild and ideal air conditions without the presence of a strong base and metal. The mechanistic studies reveal that the generation of a benzene radical the oxidative cleavage of aromatic hydrazines for the cross-coupling of C(sp)-C(sp) with the assistance of a photocatalyst is essential. The process exhibits excellent compatibility with functional groups and provides convenient access to various 3-arylquinoxalin-2(1)-ones in good to excellent yields.