Site-Selective C(sp3)−H and Switchable C(sp3)−H/C(sp2)−H Functionalization Enabled by Electron-Deficient Cp*CF3Ir(III) Catalyst and Photosensitizer

Abstract

A site-selective functionalization of a C(sp³)−H bond was achieved in the presence of an intrinsically more reactive C(sp²)−H bond by controlling the orientation of a directing group via a photo-induced E/Z isomerization of an oxime ether. By combining E/Z isomerization and an electron deficient Cp*^CF3Ir(III) catalyst, the scope of oxime ethers in C(sp³)−H functionalization was successfully expanded. Based on this strategy, the order of C−H activation was switchable and successive C(sp³)−H/C(sp²)−H and C(sp²)−H/C(sp³)−H double functionalizations were accomplished to construct densely functionalized structures.