1783-47-7Relevant academic research and scientific papers
Organometallic chemistry and catalysis on gold metal surfaces
Angelici, Robert J.
, p. 847 - 856 (2008)
As in transition metal complexes, C{triple bond, long}N-R ligands adsorbed on powdered gold undergo attack by amines to give putative diaminocarbene groups on the gold surface. This reaction forms the basis for the discovery of a gold metal-catalyzed reaction of C{triple bond, long}N-R, primary amines (R′NH2) and O2 to give carbodiimides (R′-N{double bond, long}C{double bond, long}N-R). An analogous reaction of C{triple bond, long}O, RNH2, and O2 gives isocyanates (R-N{double bond, long}C{double bond, long}O), which react with additional amine to give urea (RNH)2C{double bond, long}O products. The gold-catalyzed reaction of C{triple bond, long}N-R with secondary amines (HNR′2) and O2 gives mixed ureas RNH(C{double bond, long}O)NR′2. In another type of gold-catalyzed reaction, secondary amines HN(CH2R)2 react with O2 to undergo dehydrogenation to the imine product, RCH{double bond, long}N(CH2R). Of special interest is the high catalytic activity of gold powder, which is otherwise well-known for its poor catalytic properties.
Synthesis of urea derivatives from amines and CO2 in the absence of catalyst and solvent
Wu, Chaoyong,Cheng, Haiyang,Liu, Ruixia,Wang, Qiang,Hao, Yufen,Yu, Yancun,Zhao, Fengyu
experimental part, p. 1811 - 1816 (2011/02/22)
Urea derivatives are obtained in mild to good yield from the reactions of primary aliphatic amines with CO2 in the absence of any catalysts, organic solvents or other additives. To optimize reaction conditions, experimental variables including temperature, pressure, the concentration of amine, reaction time etc. were studied. Satisfactory yields were obtained at the optimized conditions that are comparable to the presence of catalyst and solvent. The preliminary investigation of the reaction mechanism showed that alkyl ammonium alkyl carbamate was quickly formed as the intermediate, and then the final product was formed by the intramolecular dehydration.
Non-nanogold catalysis of carbon monoxide oxidative amination
Zhu, Bolin,Angelici, Robert J.
, p. 14460 - 14461 (2008/02/02)
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). Copyright
