Kinetics and enantioselectivity of the Baeyer-Villiger oxidation of cyclohexanones by chiral tetrapyridyl oxoiron(IV) complex

The previously reported oxoiron(IV) complex, [Fe-IV(asN4Py)(O)](2+) with chiral pentadentate ligand, asN4Py (asN4Py = N,N-bis(2-pyridylmethyl)-1,2-di(2-pyridyl)ethylamine), is effective for the Baeyer-Villiger oxidation of cyclohexanone derivatives. The reaction is shown to be first order in both cyclohexanone and the oxoiron(IV) species. The second order rate constant is smaller by one order of magnitude than that obtained for the related achiral [Fe-IV(N4Py)(O)](2+) complex. Oxidation of 4-substituted cyclohexanone derivatives by the chiral oxoiron (IV) complex attains moderate enantioselectivities up to 45% enantiomeric excess (ee).