Palladium-Catalyzed C-F Bond Formation via Directed C-H Activation

Palladium-catalyzed CF bond formation via directed CH activation has recently emerged as a significant method to introduce fluorine atoms into organic molecules in an atom- and step-economical path. At the interface between fluorine chemistry and synthetic organic chemistry, the development of direct fluorinations of the CH bond remains sluggish, due to the major challenge of reductive elimination to afford the CF bond. One strategy is to oxidize palladium(II) species to more electron-deficient palladium(IV or III) fluorides to promote the CF bond forming reductive elimination, which opens up palladium-catalyzed CH fluorination as a powerful transformation. This focused review gives a brief summary of the mere handful of examples, including C(sp(2))F and C(sp(3))F bond formations, in this field so far.