Photocatalytic C-C Bond Activation of Oxime Ester for Acyl Radical Generation and Application

A unified strategy to generate acyl radical from oxime ester via selective C-C bond activation is reported. Under visible-light irradiation, single-electron transfer from fac-Ir(ppy)(3) to related oxime takes place followed by a fast beta-fragment of C-C bond to yield aryl and aliphatic acyl radicals, subsequently captured by diverse Michael acceptors. More interestingly, the single-electron transfer enables coupling with energy transfer of the excited fac-Ir(ppy)(3) via enone intermediate formed in situ for cyclobutane formation.