Direct electrochemical construction of C─O bonds through C(sp3)─H functionalization still remains fundamentally challenging. Here, electrochemical oxidation-induced benzylic and allylic C(sp3)─H etherification has been developed. This protocol not only offers a practical strategy for the construction of C─O bonds using nonsolvent amounts of alcohols but also allows direct electrochemical benzylic and allylic C(sp3)─H functionalization in the absence of transition metal catalysis. A series of alcohols and benzylic and allylic C(sp3)─H compounds were compatible with this transformation. Mechanistically, the generation of aryl radical cation intermediates is the key to this C(sp3)─H etherification, as evidenced by radical probe substrate (cyclopropane ring opening) and electron paramagnetic resonance experiments.

A one-pot three-component reaction for the regioselective synthesis of thioarylated imidazoheterocycles from aryl halides and elemental sulfur using copper(I) iodide as a catalyst has been developed. Reactions proceed with high efficiency and afford thioarylated imidazoheterocycles in good yields with broad functional group tolerance.

The regioselective C-H amination of quinoline amides (C5) and imidazopyridines (C3) under transition-metal-free conditions at room temperature with a high degree of functional group tolerance is reported. The C-H amination promoted by visible light in the presence of a photocatalyst with a wide range of heteroamines makes the present protocol more sustainable.