Gold Nanocluster as a Unique Catalyst under Ambient Condition

摘要: Metallic Gold has been believed to be catalytically inactive due to its high ionization potential and the lack of adsorption ability. In contrast, nanometer-sized gold clusters exhibit catalytic activity especially toward the aerobic oxidation reactions. We have recently demonstrated the preparative method and its excellent catalytic activity of gold nanoclusters stabilized by hydrophilic polymers such as poly-N-vinyl-2-pyrrolidone (PVP) toward the aerobic oxidation including alcohol oxidation [1-3]. The key active species of these aerobic oxidation reactions is believed to be the electron-deficient surface of Au, generated by the adsorption of molecular oxygen as a superoxo-like form. We found that Au: PVP also works as a formal Lewis acid to catalyze the intramolecular addition of alcohol [4], toluenesulfonamide [5], or primary amine to unactivated alkenes under aerobic conditions. These addition reactions did not proceed …