Switchable Direct Oxygenative Arylation of C(sp³)–H Bonds via Electrophotocatalysis

A metal-free electrophotochemical C(sp3)-H arylation was developed under mild conditions. This method enables a switchable synthesis of diaryl alcohols and diaryl alkanes from inactive benzylic carbons. More importantly, a cheap and safe mediator N-chlorosuccinimide (NCS) was developed, which was employed for the hydrogen atom transfer (HAT) process of the benzylic C–H bond. In addition, this active radical was captured and identified by electron paramagnetic resonance (EPR).