Mechanism of the Selective Functionalization of Saturated Hydrocarbons by Gif Systems: Relationship with Methane Monooxygenase

Two intermediates, A and B, have been identified in the selective oxidation of saturated hydrocarbons to ketones by Gif-type systems. Intermediate A has been characterized as an Fevspecies with a secondary iron σ-bond to carbon; it is captured by four different reagents or transformed into the second intermidiate, B, which hydrolyzes to form a secondary alcohol. A μ-oxo Fe2 IIIdimer is proposed as a basis for Gif-type reactivity. If the first iron is involved in the synthesis of intermediate A, the second is used to oxidize intermediate B intramolecularly to a ketal, which on hydrolysis yields a ketone. The enzyme methane monooxygenase shows a remarkable similarity to Gif-type systems in its selective hydrocarbon oxidation, particularly in the case of adamantane.