Photocatalytic C(sp3)–H bond functionalization by Cu(i) halide cluster-mediated O2 activation

Abstract

Photocatalytic C–H bond activation is a challenging approach to selectively functionalize C(sp³)–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(sp³)–H bonds with unreactive O₂ upon light irradiation. This modern protocol promises a photoinduced SET process between Cu(I)-clusters and O₂, and possibly forms Cu(II)–O₂˙⁻ species for abstracting the H-atom from the C(sp³)–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.