The selective functionalization of saturated hydrocarbons: recent developments in Gif chemistry

The Gif systems permit the selective functionalization of saturated hydrocarbons under mild conditions and with high efficiencies. A newly discovered Fe-II-Fe-IV manifold is shown to form alkyl chlorides by a process involving carbon-centered radicals as intermediates. This 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 for hydrocarbon activation has been demonstrated. The ligand environment of the catalyst in solution is clarified using quantitative C-13-NMR spectroscopy. Evidence for a mu-peroxo dimer species as a key intermediate in solution is provided and recent mechanistic studies are reported.