Non-Nanogold Catalysis of Carbon Monoxide Oxidative Amination

Bulk metallic gold particles (∼1000 nm) catalyze the reaction of CO, O₂, and primary amines (R−NH₂) to give ureas (RNH)₂CO. Isocyanates (R−NCO) are identified as intermediates in the reactions and are shown to react with primary and secondary amines to give ureas under the conditions of the gold-catalyzed reactions. Although many recent studies indicate that nanosized particles of gold are required for the catalytic oxidation of CO, the results presented in this paper show that bulk gold is capable of catalyzing the oxidative amination of CO under mild conditions (45 °C, 1 atm CO and O₂).