Visible light-induced aerobic oxidation of diarylalkynes to α-diketones catalyzed by copper-superoxo at room temperature

We have developed the visible light induced simple copper(II) chloride catalyzed oxidation of diarylacetylenes to alpha-diketones by molecular oxygen at room temperature. The in situ generated copper(II)-superoxo complex is a light-absorbing species that oxidizes inert diarylacetylenes to a-diketones. In contrast to reported photochemical processes, the current oxidation protocol does not require any exogenous photocatalyst or radical initiator. The green chemistry metrics evaluation signifies that the E-factor for the current oxidation process is similar to 2.3 times better than that of reported photochemical processes. The current reaction scores 63 on the EcoScale of 0-100, indicating an adequate synthesis process. Thus, the overall oxidation process is simple, environmentally benign, and economically feasible.