Aerobic Benzylic C(sp3)-H Bond Oxygenations Catalyzed by NBS under Visible Light Irradiation

J Org Chem. 2024 Jan 5;89(1):534-540. doi: 10.1021/acs.joc.3c02284. Epub 2023 Dec 22.

Abstract

An efficient photocatalytic oxidation of benzylic C(sp3)-H bonds to ketones, esters, and amides has been developed using NBS as a metal-free photocatalyst and O2 as an oxidant. A variety of synthetically and biologically valuable compounds are assembled in moderate to excellent yields. The synthetic utility of this approach has been demonstrated by gram-scale experiments. A possible free radical mechanism was proposed to rationalize the reaction procedure.