Oxidative Aliphatic C-H Fluorination with Fluoride Ion Catalyzed by a Manganese Porphyrin

Fluorine's Smooth Introduction Carbon-fluorine bonds are emerging as increasingly versatile constituents of drugs, agrochemicals, and positron emission tomography tracers. Elemental F 2 gas is in principle an efficient reagent for their preparation, but its extreme reactivity requires special handling precautions. Substantial research has therefore focused on promoting selective reactivity of more conveniently handled fluoride ion salts. Liu et al. (p. 1322 ) present a manganese catalyst that transfers fluoride to a range of hydrocarbons in conjunction with a hypervalent iodine-based oxidant. Mechanistic studies implicate a manganese difluoride intermediate that reacts with alkyl radicals generated by a preceding manganese oxo.