Nonheme Diiron Oxygenase Mimic That Generates a Diferric–Peroxo Intermediate Capable of Catalytic Olefin Epoxidation and Alkane Hydroxylation Including Cyclohexane

Herein are described substrate oxidations with H₂O₂ catalyzed by [Fe^II(IndH)(CH₃CN)₃](ClO₄)₂ [IndH = 1,3-bis(2′-pyridylimino)isoindoline], involving a spectroscopically characterized (μ-oxo)(μ-1,2-peroxo)diiron(III) intermediate (2) that is capable of olefin epoxidation and alkane hydroxylation including cyclohexane. Species 2 also converts ketones to lactones with a decay rate dependent on [ketone], suggesting direct nucleophilic attack of the substrate carbonyl group by the peroxo species. In contrast, peroxo decay is unaffected by the addition of olefins or alkanes, but the label from H₂¹⁸O is incorporated into the the epoxide and alcohol products, implicating a high-valent iron–oxo oxidant that derives from O–O bond cleavage of the peroxo intermediate. These results demonstrate an ambiphilic diferric–peroxo intermediate that mimics the range of oxidative reactivities associated with O₂-activating nonheme diiron enzymes.