Ionic liquids as reaction media in catalytic oxidations with manganese and iron pyridyl triazacyclononane complexes

A family of bioinspired iron and manganese complexes of general formula [M-II(CF3SO3)(2)((Me, X)PyTACN)], where (Me,X)PyTACN = 1-[2 '-(6-Rpyridyl)methyl]-4,7-dimethyl-1,4,7-triazacyclononane, R=H, Me and M = Fe, and Mn has been studied as efficient catalytic systems for hydrogen peroxide oxidation reactions. Previous work revealed that the manganese derivative [Mn-II(CF3SO3)(2)((Me, H)PyTACN)], 1, in acetonitrile exhibits a high catalytic activity in the epoxidation of a wide range of olefins (TON: 810-4500), using acetic acid and hydrogen peroxide as primary oxidant. The analogous iron based complex [Fe-II(CF3SO3)(2) (Me, HPyTACN)], 2a and [Fe-II(CF3SO3)(2)((Me,Me)PyTACN)], 2b promote the high added value oxidation reaction of alkanes in mild conditions. In this work sustainability and selectivity of the oxidative system is improved with the use of the ionic liquids (ILs) as reaction medium. The possibility to recycle the catalytic phase without loss of the activity with respect to the original reaction in acetonitrile (MeCN) is reported. (C) 2013 Elsevier B. V. All rights reserved.