Evolution of Earth‐Abundant 3 d‐Metallaelectro‐Catalyzed C−H Activation: From Chelation‐Assistance to C−H Functionalization without Directing Groups

Catalyzed C−H functionalizations have emerged as a transformative platform for molecular syntheses. Despite of indisputable advances, oxidative C−H activations have been largely restricted to precious transition metals and stoichiometric amounts of chemical oxidants. In contrast, we herein discuss the potential of earth‐abundant, environmentally‐benign 3d transition metals for C−H activation, which has recently gained major momentum. Thus, a strategy for full resource economy has been established in our group, with green electricity as a renewable redox agent, giving valuable hydrogen as the sole byproduct under redox mediator‐free conditions. In this account, we detail our accomplishments in 3d metallaelectrocatalysis towards green syntheses until March 2021. Electrochemical C−H activation by 3d transition metals, under redox mediator‐free condition has enabled ideal resource‐economy. Exceedingly mild reaction conditions have largely been achieved by oxidation‐induced reductive elimination.