Oxidation of hydrocarbons by ruthenium-oxo complexes

Selective oxidation of saturated hydrocarbons to the corresponding alcohols/ketones under mild conditions still remains one of the most important challenges in homogeneous catalysis. Among the transition metal complexes investigated, those oxo complexes of ruthenium and manganese are found to be very reactive, capable of oxidizing saturated alkanes under suitable choice of reaction conditions. However, there is still a lack of understanding of the factors governing the rate of alkane oxidation because the reactive manganese and ruthenium-oxo species are very difficult to be generated and characterized. In this paper, an overall picture of the reactivities of ruthenium-oxo complexes with π-aromatic diimines, macrocyclic tertiary amines, and porphyrins as ligands is discussed.