In this paper,we have developed a highly efficient method for the direct preparation of propylene carbonate from propylene and carbon dioxide（CO2） using quaternary ammonium heteropolyphosphatotungstate–quaternary a...In this paper,we have developed a highly efficient method for the direct preparation of propylene carbonate from propylene and carbon dioxide（CO2） using quaternary ammonium heteropolyphosphatotungstate–quaternary ammonium halide catalytic system with anhydrous hydrogen peroxide as an oxidant through one-pot two-step process.The effects of the amount of tetrabutylammonium bromide（TBAB）,the concentration of hydrogen peroxide and other reaction conditions were investigated.The catalyst system gave an optimum propylene oxide yield（91%） at75°C in oxidation step and the highest propylene carbonate yield（99%） at 140°C and 3.0 MPa in cycloaddition step.Based on the results,a reaction mechanism has been proposed.展开更多
An eco-friendly synthesis of cyclododecanone (CDON) from cyclododecatriene (CDT) is described. Selec- tive epoxidation of CDT with hydrogen peroxide using hexadecyl trimethyl ammonium heteropolyphospha- totungstate [(...An eco-friendly synthesis of cyclododecanone (CDON) from cyclododecatriene (CDT) is described. Selec- tive epoxidation of CDT with hydrogen peroxide using hexadecyl trimethyl ammonium heteropolyphospha- totungstate [(n-C16H33NMe3)3PW4O16, HAHPT] as catalyst and water as solvent followed by the hydrogena- tion on Raney nickel catalyst gave cyclododecanol (CDOL). The latter was oxidized with hydrogen peroxide using HAHPT as catalyst and a mixture of water and t-butanol as solvent to afford CDON. The total yield was 53.4% under the optimum reaction conditions.展开更多
文摘In this paper,we have developed a highly efficient method for the direct preparation of propylene carbonate from propylene and carbon dioxide（CO2） using quaternary ammonium heteropolyphosphatotungstate–quaternary ammonium halide catalytic system with anhydrous hydrogen peroxide as an oxidant through one-pot two-step process.The effects of the amount of tetrabutylammonium bromide（TBAB）,the concentration of hydrogen peroxide and other reaction conditions were investigated.The catalyst system gave an optimum propylene oxide yield（91%） at75°C in oxidation step and the highest propylene carbonate yield（99%） at 140°C and 3.0 MPa in cycloaddition step.Based on the results,a reaction mechanism has been proposed.
文摘An eco-friendly synthesis of cyclododecanone (CDON) from cyclododecatriene (CDT) is described. Selec- tive epoxidation of CDT with hydrogen peroxide using hexadecyl trimethyl ammonium heteropolyphospha- totungstate [(n-C16H33NMe3)3PW4O16, HAHPT] as catalyst and water as solvent followed by the hydrogena- tion on Raney nickel catalyst gave cyclododecanol (CDOL). The latter was oxidized with hydrogen peroxide using HAHPT as catalyst and a mixture of water and t-butanol as solvent to afford CDON. The total yield was 53.4% under the optimum reaction conditions.
