Iron Catalyzed Double Bond Isomerization: Evidence for an Fe ^I /Fe ^III Catalytic Cycle

Iron-catalyzed isomerization of alkenes is reported using an iron(II) ?-diketiminate pre-catalyst. The reaction proceeds with a catalytic amount hydride source, such as pinacol borane (HBpin) or ammonia (H3N?BH3). Reactivity both allyl arenes and aliphatic has been studied. mechanism was investigated by variety means, including deuteration studies, Density Functional Theory (DFT) Electron Paramagnetic Resonance (EPR) spectroscopy. data obtained support pre-catalyst activation step that gives access to ?2-coordinated alkene FeI complex, followed oxidative addition the give FeIII intermediate, which then undergoes reductive elimination allow release product.