Dioxygen Activation by a Non-Heme Iron(II) Complex: Formation of an Iron(IV)−Oxo Complex via C−H Activation by a Putative Iron(III)−Superoxo Species

Iron(III)−superoxo intermediates are believed to play key roles in oxygenation reactions by non-heme iron enzymes. We now report that a non-heme iron(II) complex activates O₂ and generates its corresponding iron(IV)−oxo complex in the presence of substrates with weak C−H bonds (e.g., olefins and alkylaromatic compounds). We propose that a putative iron(III)−superoxo intermediate initiates the O₂-activation chemistry by abstracting a H atom from the substrate, with subsequent generation of a high-valent iron(IV)−oxo intermediate from the resulting iron(III)−hydroperoxo species.