Photocatalytic C(sp)-H bond functionalization by Cu(I) halide cluster-mediated O activation.

Photocatalytic C-H bond activation is a challenging approach to selectively functionalize C(sp)-H bonds with dioxygen under mild conditions. Herein, by merging transition metal- and photo-catalysis, photoactive Cu(I)-halide(X) (X = Cl, Br, I) clusters are employed to effectively catalyse the selective monooxygenation and C-C oxidative cross-coupling of C(sp)-H bonds with unreactive O upon light irradiation. This modern protocol promises a photoinduced SET process between Cu(I)-clusters and O, and possibly forms Cu(II)-O˙ species for abstracting the H-atom from the C(sp)-H bond. This process produces alkyl radicals to react with OOH or nucleophiles for oxidation or cross-coupling products, advancing the Cu(I)-cluster mediated photoredox catalysis toward functional fine chemicals with pursued selectivity.