Efficient Synthesis of Imines by Oxidative Coupling Catalyzed by Ce-Mn Oxide Microspheres

Abstract

Oxidative self-coupling of amines and cross-coupling with alcohols are important reactions for the synthesis of imines; however, catalytic systems for these reactions usually require expensive oxidant, complicated catalyst preparation, complex reaction set-up, and/or additives such as bases or cocatalysts. Here, we report that amorphous cerium-manganese (Ce−Mn) oxides with hierarchical microsphere structure prepared by a facile method could exhibit excellent catalytic performance for the synthesis of various imines using air as the green oxidant under mild conditions. The Ce−Mn oxide heterogeneous catalysts could also be easily recovered and efficiently recycled without significant loss of activities. The excellent activities and the reusability of the Ce−Mn oxide microspheres offer potential advances in the synthesis of imine.