Evidence for a High-Valent Iron-Fluoride That Mediates Oxidative C(sp 3 )-H Fluorination.

[Fe II (NCCH 3 )(NTB)](OTf) 2 (NTB = tris(2-benzimidazoylmethyl)amine, OTf = trifluoromethanesulfonate) was reacted with difluoro(phenyl)-λ 3 -iodane (PhIF 2 ) in the presence of a variety of saturated hydrocarbons, resulting in the oxidative fluorination of the hydrocarbons in moderate-to-good yields. Kinetic and product analysis point towards a hydrogen atom transfer oxidation prior to fluorine radical rebound to form the fluorinated product. The combined evidence supports the formation of a formally Fe IV (F) 2 oxidant that performs hydrogen atom transfer followed by the formation of a dimeric μ-F-(Fe III ) 2 product that is a plausible fluorine atom transfer rebound reagent. This approach mimics the heme paradigm for hydrocarbon hydroxylation, opening up avenues for oxidative hydrocarbon halogenation.