Development fo Mn(Ⅲ)(Schiff Base) Complexes for the Catalyst of Olefin Oxygenation to Alcohols in the Presence of NaBH4

Molecular oxygen would be the most desirable oxidant in organic synthesis in terms of costs and environmental considerations.Efforts have long been focused on the development of O2-mediated oxidation methods.1 We have reported previously the oxidative conversion of olefins to the alcohols, where molecular oxygen was used as the oxidant.In this process, we used a (salen)Mn(III)Cl complex 1 as the catalyst and sodium borohydride as the one-oxygen reducing agent.2Even though this process was performed under mild conditions, only conjugated vinyl arene substrates were oxidized with high efficiency (Eq.1).Other olefin substrates, for example non-conjugated or non-vinylic olefins, showed very low reactivity.Therefore, we decided to develop better oxidation catalysts, which could be applicable to the variety of simple olefins.