Visible-light-assisted aerobic photocatalytic oxidation of amines to imines over NH2-MIL-125(Ti)

NH2-MIL-125(Ti), an amine-functionalized metal-organic-framework (MOF), was found for the first time to exhibit photocatalytic activity for the aerobic selective oxidation of amines to imines under visible light irradiations, Different amines can be effectively transformed to imines using O-2 over NH2-MIL-125(Ti) under visible light irradiation. The photo-generated Ti3+ and O-center dot(2)- which was formed via the reaction between Ti3+ and O-2, are proposed to be involved in this transformation process based on the experimental observations and the ESR result. This work provides an economical, sustainable and green process for amines transformations and highlights the great potential of MOFs as photocatalysts for organic syntheses. (C) 2014 Elsevier B.V. All rights reserved.