杂多酸催化环酮的 Baeyer-Villiger 氧化反应

摘要

以30% H2 O2作为氧化剂，在温和条件下，考察了三种 Keggin 型结构的杂多酸催化环酮 Baeyer-Villiger 氧化反应的性能。结果表明，在选择的三种杂多酸中，硅钨酸表现出最高的催化性能，能使大多数环酮转化成相应的内酯，转化率可以达到90%。并且，在优化反应条件以后，有很好的选择性。催化剂重复使用三次以后，催化活性和选择性并没有明显的降低。在相同条件下，磷钨酸和磷钼酸也表现了良好的催化活性和选择性。利用核磁共振(NMR)对反应后的产物进行了表征。%Three Keggin heteropoly acids were used as catalysts for Baeyer-Villiger oxidation of cyclic ketones under mild conditions using hydrogen peroxide as oxidant. The optimum oxidation condition was well investigated. It was found that all the three catalysts, especially the silicotungstic, showed high catalytic activity in the Baryer-Villiger oxidation of ketones, and selected ketones were converted to the corresponding lactones and high selectivities under the optimum reaction conditions. The catalysts could be reused three times without obvious loss of activity and selectivity in the oxidation. All of the samples were characterized by Nuclear Magnetic Resonance (NMR).