Visible light-driven copper(ii) catalyzed aerobic oxidative cleavage of carbon-carbon bonds: a combined experimental and theoretical study

By switching on visible blue light, aerobic oxidation of various substrates, such as α-substituted, β-substituted and α-halo styrenes, was first realized with a copper(ii) catalyst. Subsequent Cu(ii)-catalyzed photo-oxygenation of alkynes, aldehydes and carboxylic acids was extended and the new catalytic system was proven to be reliable towards functional group tolerance. For all classes of substrates examined, the oxidized products were isolated in good yields and were found to be highly chemoselective. Through computational studies employing density functional theory (DFT) and experimental support, the identity of the active catalytic species was proposed as a μ4-oxido copper chloride cluster [Cu4OCl6]. DFT modelling was engaged in examining the reactivity of this copper chloride cluster catalyst, outlining viable reaction pathways for the oxidative transformation of the styrenes.