A General Strategy for C(sp)─H Bond Etherification via Quinoline Derivative-Mediated Electrolysis.

Electrooxidative coupling of C(sp)─H bonds with nucleophiles offers an attractive method for constructing C─C and C─X bonds without sacrificial oxidants. However, the direct electrochemical approach requires the nucleophilic reagent to have a higher potential than the C(sp)─H coupling partners, which restricts the substrate scope. In this study, a quinoline derivative is introduced as an electrochemical mediator, enabling efficient C─H bond etherification with reduced reliance on the electronic properties of substrates. The catalytic system demonstrates broad substrate compatibility, extending to C(sp)─H coupling partners featuring a diverse range of C─H bonds, including tertiary benzylic C─H bonds and unactivated C(sp)─H bonds. Mechanistic investigations confirm the role of the electrocatalyst in the hydrogen atom transfer (HAT) process. This method provides a versatile and efficient strategy for the late-stage functionalization of bioactive molecules.