| 摘要 |
PURPOSE:The oxidation reaction of an alpha,beta-unsaturated aliphatic aldehyde and an alcohol with molecular oxygen is conducted in the presence of a specific catalyst to produce in one step an alpha,beta-unsaturated carboxylic ester in high yield and selectivity. CONSTITUTION:The oxidation reaction of an alpha,beta-unsaturated aliphatic aldehyde of formula I (R1-3 are H or alkyl) and an alcohol of formula: R4-OH (R4 is 1-10C alkyl) such as methanol with molecular oxygen is conducted in the presence of a catalyst consisting of (a) at least one from Pd and its compounds, (b) at least one from T1, Hg and their compounds and (c) calcium carbonate at room temperature and atmospheric pressure to produce the objective compound of formula II such as methyl methacrylate. The component Pd is preferably Pd metal and the component T1 or Hg is preferably oxide, hydroxide or acetate of these metals. Activated carbon may be used as a carrier; however, most perferably Pd metal and thallium acetate or mercury acetate are supported on calcium carbonate. |
