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 α-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 α-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 ∼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.