Thiyl radical catalyzed oxidation of diarylalkynes to α-diketones by molecular oxygen under visible-light irradiation

A facile synthesis of diaryl 1,2-diketones from diarylalkynes under visible-light irradiation was developed. The reaction proceeded smoothly through a thiyl radical catalyzed oxidation by molecular oxygen under mild conditions and generated the desired products in excellent yields with good tolerance of functional groups.