Transition-metal-catalyzed C(sp3)–H bond fluorination reactions

Constructing C−F bonds via C−H activation has been a subject of considerable attention in the field of organic synthesis. Within this reaction class, the popularity of transition-metal-catalyzed approaches has substantially expanded in recent years. Currently, there are two main types of these reaction pathways. The first type involves the formation of a carbon-metal-fluorine intermediate with the assistance of a directing group. The second type utilizes a transition metal species to generate a radical or carbocation intermediate. Despite the importance of these reactions, there has yet to be a comprehensive review of transition-metal-catalyzed C(sp3)−H bond fluorination processes. This review presents major advances in and detailed mechanistic discussions of transition-metal-catalyzed C(sp3)−H bond fluorination reactions with different reaction modes under various thermal, photochemical, and electrochemical conditions.