Two faces of a biomimetic non-heme HO-Fe^V=O oxidant: Olefin epoxidation versus cis-dihydroxylation

(Figure Presented) Reactivity along two channels is shown by the HO-Fe ^V=O species responsible for Fe(tpa)-catalyzed olefin oxidation (tpa = tris(2-pyridylmethyl)amine). Attack of the oxo ligand on an olefinic carbon atom yields epoxide and attack of the hydroxo ligand affords cis-diol (see scheme). Hybrid density functional theory now demonstrates that the two processes have comparable activation energies.