Hydrocarbon oxidation with H2O2, catalyzed by iron complexes with a polydentate pyridine-based ligand

We report the structural and functional features of two new catalysts: a mononuclear [Fe(N5mpy)(CH3CN)](BF4)2 (N5mpy = (N,N′E,N,N′E)-N,N′-(pyridine-2,6-diylbis(ethan-1-yl-1-ylidene))bis(1-(pyridin-2-yl)methanamine)) complex and a binuclear {[Fe(N5mpy)]2O}(BF4)4 complex. Both compounds catalyze the oxidation of alkanes by H2O2, in MeCN or acetone to yield alcohols and ketones. Moderate to good yields are obtained with various cyclic and benzylic alkanes. Screening of several substrates revealed that higher yields are obtained for the oxidation of alkanes with low C-H bond dissociation energies. The ratio alcohol/ketone observed suggests the involvement of iron-based oxidizing species.