High‐Valent‐Cobalt‐Catalyzed C−H Functionalization Based on Concerted Metalation–Deprotonation and Single‐Electron‐Transfer Mechanisms

C−H functionalization has been established as a powerful strategy for the commercial construction of organic molecules. This review encompasses the most recent advances in C−H activation catalyzed by earth‐abundant cobalt complexes, involving two types of fundamental reaction paths, that is, the concerted metalation–deprotonation (CMD) path associated with non‐oxidative C−H activation and the intermolecular single‐electron‐transfer (SET) path. Transformations catalyzed by high‐valent cobalt based on the two mechanisms and used in organic syntheses, including those involving C−C and C−X (X=O and N) bond formation, are herein presented.