Site‐selective C(sp3)–H and Switchable C(sp3)–H/C(sp2)–H Functionalization Enabled by Electron‐deficient Cp*CF3Ir(III) Catalyst and Photosensitizer

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.