Organic solvent- and phase transfer catalyst-free oxida-tion of cyclohexanol to cyclo-hexanone with dilute H2O2

The oxidation of cyclohexanol to cyclohexanone with 30% aqueous hydrogen peroxide by using peroxotungstate complexes formed in situ from sodium tungstate dihydrate and various bidentate organic ligands as the catalysts, without organic solvents, halide and phase transfer catalyst has been carried out. The influence of 13 ligands on the oxidation is investigated. The maximum yield of cyclohexanone is obtained when using 1,10-phenanthroline (96%) and oxalic acid (95%) as the ligand. Very high yields (around 90%) have also been obtained for the instances of using salicylic acid, 3,5-dibromosalicylic acid, and 8-hydro- xylquinoline as ligands. A research to improve the reaction condition using cheap oxalic acid as the ligand indicates that the optimum condition is that the reaction mixture with a molar ratio of cycohexanol︰tungstate dihydrate︰oxalic acid︰30% H2O2=100︰2︰2︰120 was stirred at 85-90℃ for 12 h.     

Organic solvent- and phase transfer catalyst-free oxidation of cyclohexanol to cyclohexanone with dilute H2O2

The oxidation of cyclohexanol to cyclohexanone with 30% aqueous hydrogen peroxide by using peroxotungstate complexes formed in situ from sodium tungstate dihydrate and various bidentate organic ligands as the catalysts, without organic solvents, halide and phase transfer catalyst has been carried out. The influence of 13 ligands on the oxidation is investigated. The maximum yield of cyclohexanone is obtained when using 1,10-phenanthroline (96%) and oxalic acid (95%) as the ligand. Very high yields (around 90%) have also been obtained for the instances of using salicylic acid, 3,5-dibromosalicylic acid, and 8-hydro- xylquinoline as ligands. A research to improve the reaction condition using cheap oxalic acid as the ligand indicates that the optimum condition is that the reaction mixture with a molar ratio of cycohexanol︰tungstate dihydrate︰oxalic acid︰30% H₂O₂=100︰2︰2︰120 was stirred at 85—90℃ for 12 h. :     

双季铵盐和钨酸钠催化下双氧水溶液清洁氧化醇和烯烃

利用三种双季铵盐和钨酸钠催化体系，在无有机溶剂条件下，实现了30％过氧化氢水溶液清洁催化氧化环己醇、苯甲醇、环己烯为环己酮、苯甲醛(苯甲酸)、己二酸；考察了不同催化体系的催化性能．实验结果表明，钨酸钠和双季铵盐催化体系能在温和的条件下，催化稀过氧化氢溶液氧化环己醇、苯甲醇、环己烯，其中，己二酸、苯甲酸、苯甲醛、环己酮的最高产率分别为：74．92％，91．37％，94．51％，82．17％．苯甲醇氧化时，随过氧化氢加入量的不同，可以选择性地给出苯甲醛和苯甲酸．