The selective functionalization of saturated hydrocarbons. Part 32. Distinction between the Fe II –Fe IV and Fe III –Fe V manifolds in Gif chemistry. The importance of carboxylic acids for alkane activation. Evidence for a dimeric iron species involved in Gif-type chemistry

Gif chemistry permits the selective functionalization of saturated hydrocarbons under very mild conditions. The formation of alkyl chlorides is shown to derive from an FeII–FeIV manifold and is distinct from the usual ketonization process (Gif chemistry) produced by an FeIII–FeV manifold. The importance of certain carboxylic acids such as picolinic acid 1 for hydrocarbon activation is highlighted. The ligand environment of the catalyst in solution is clarified using 13C NMR spectroscopy. Evidence for a µ-peroxo-dimer species as a key intermediate in solution is provided.