One-potN-alkylation of primary amines to secondary amines by gold clusters supported on porous coordination polymers

Abstract

Gold clusters and nanoparticles were deposited on the three kinds of porous coordination polymers (PCP5), MOF-5, CPL-2, and AI-MIL53 by the solid grinding method. The size of Au particles depended on the kinds of PCPs and increased in the order of AI-MIL53 < CPL-2 < MOF-5. The mean diameter of Au particles supported on AI-MIL53 was estimated to be 1.6 nm by HAADFSTEM. Such small Au clusters on AI-MIL53 can catalyze one-pot synthesis of secondary amines from primary amines by sequential oxidation/hydrogenation owing to the remarkable improvement of hydrogenation efficiency of imine. Gold clusters deposited on AI-MIL53 can also promoteN-alkylation of amine with alcohol to form a secondary amine under N2 atmosphere without using O2 and H2.