The reactivity of amononuclear high-spin iron(III)-OTf = trifluoromethanesulfonate] with cumyl hydroperoxide (CmOOH), towardt he C À H and C=Cbonds of hydrocarbons is reported. 2 oxygenates the strong CÀHbonds of aliphatic substrates with high chemo-and stereoselectivity in the presence of 2,6-lutidine.While 2 itself is as luggish oxidant, 2,6-lutidine assists the heterolytic OÀO bond cleavage of the metal-bound alkylperoxo,g iving rise to areactive metal-based oxidant. The roles of the urea groups on the supporting ligand, and of the base,indirecting the selective and catalytic oxygenation of hydrocarbon substrates by 2 are discussed.