Transition-metal-mediated fluorination of arenes

A selection of aromatic carbon-fluorine bond-forming reactions is presented with particular focus on transition-metal-mediated fluorination. Introductory comments on the importance and application of fluorinated organic molecules are followed by an overview of conventional fluorination reactions including nucleophilic aromatic substitution, electrophilic aromatic substitution, and the Balz-Schiemann reaction. A discussion of the recent development of the fluorination reactions mediated by palladium and silver is presented. This review focuses on the mechanisms of the presented fluorination reactions as well as the conceptual difficulty associated with transition-metal-mediated carbon-fluorine bond formation in contrast to other carbon-heteroatom bond formation.