The selective functionalization of saturated hydrocarbons. Part 32. Distinction between the FeII–FeIV and FeIII–FeV manifolds in Gif chemistry. The importance of carboxylic acids for alkane activation. Evidence for a dimeric iron species involved in Gif-type chemistry

Abstract

Gif chemistry permits the selective functionalization of saturated hydrocarbons under very mild conditions. The formation of alkyl chlorides is shown to derive from an Fe^II–Fe^IV manifold and is distinct from the usual ketonization process (Gif chemistry) produced by an Fe^III–Fe^V 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.