Photoinduced HBr-catalyzed C-Si bond cleavage of benzylsilanes and their subsequent oxidation into benzoic acids with air as the terminal oxidant

A photoinduced highly efficient C-Si bond cleavage reaction of benzylsilanes under the catalysis of HBr was developed. The in situ generated benzyl radical intermediates were aerobically oxidized into benzoic acids highly chemoselectively. In this transformation, HBr not only acted as the single electron transfer mediator for the initial C-Si bond cleavage, but also efficiently catalyzed the oxidation of benzaldehyde intermediates into benzoic acids.