l-Proline derived mimics of the non-haem iron active site catalyse allylic oxidation in acetonitrile solutions

Non-haem iron complexes are important reagents for the oxidative functionalisation of C–H bonds. Peptidomimetic ligands derived from l-proline, pyridine-2,6-dimethanol and pyridine-2,6-dicarboxylic acid have been combined with iron(II) triflate and hydrogen peroxide in acetonitrile. The resulting complexes convert cyclohexene into the allylic oxidation products, 2-cyclohexen-1-ol, 2-cyclohexen-1-one and 2-cyclohexenyl hydroperoxide in high turnover yields. A mechanism for product formation is proposed, in which the hydroperoxy radical (HOO) is the active oxidant.