The hydroformylation of 1-hexene catalyzed by rhodium-TPPTS complexes in the ionic liquid [bmim]BF 4 was studied. The activity and selectivity of the rhodium-TPPTS complexes in [bmim]BF 4 were much higher than those r...The hydroformylation of 1-hexene catalyzed by rhodium-TPPTS complexes in the ionic liquid [bmim]BF 4 was studied. The activity and selectivity of the rhodium-TPPTS complexes in [bmim]BF 4 were much higher than those reported in other ionic liquids. The TOF of 1-hexene and selectivity for aldehyde were 1508 h -1 and 92%, respectively, under the optimum conditions. The high activity of the catalyst is ascribed to the absence of halide ions as well as the much higher solubility of hydrogen and rhodium-TPPTS complexes in [bmim]BF 4 than in [bmim]PF 6.展开更多
The preparation of aryl amides by selective oxidation of aryl nitriles using sodium tungstate as catalyst and sodium percarbonate or sodium carbonate-hydrogen peroxide as the oxidant in a methanol and water solution w...The preparation of aryl amides by selective oxidation of aryl nitriles using sodium tungstate as catalyst and sodium percarbonate or sodium carbonate-hydrogen peroxide as the oxidant in a methanol and water solution was studied. Aryl nitriles were converted to aryl amides with very high selectivity of 95%～100% at room temperature. The reactivity of aryl nitriles decreased with increasing their branched chain length. In the oxidation of tolunitriles, the oxidation rate of p-tolunitrile and m-tolunitrile was very fast, but the oxidation rate of o-tolunitrile was very slow. The oxidation rate of p-haloid aryl nitriles and p-nitro aryl nitrile decreased in the order p-nitrobenzonitrile >p-chlorobenzonitrile>p-bromobenzonitrile, while the selectivity for aryl amides was maintained at a high level of 98%～100%. The comparison of the two oxidants showed that when sodium carbonate-hydrogen peroxide was used as oxidant, the oxidation rate and selectivity were better than that when percarbonate was used. The sodium tungstate catalyst and carbonate can be reused and the catalytic activity and selectivity did not change if a suitable amount of hydrogen peroxide was supplied. This work provides a convenient method for the preparation of aryl amides from aryl nitriles under very mild reaction conditions.展开更多
文摘The hydroformylation of 1-hexene catalyzed by rhodium-TPPTS complexes in the ionic liquid [bmim]BF 4 was studied. The activity and selectivity of the rhodium-TPPTS complexes in [bmim]BF 4 were much higher than those reported in other ionic liquids. The TOF of 1-hexene and selectivity for aldehyde were 1508 h -1 and 92%, respectively, under the optimum conditions. The high activity of the catalyst is ascribed to the absence of halide ions as well as the much higher solubility of hydrogen and rhodium-TPPTS complexes in [bmim]BF 4 than in [bmim]PF 6.
文摘The preparation of aryl amides by selective oxidation of aryl nitriles using sodium tungstate as catalyst and sodium percarbonate or sodium carbonate-hydrogen peroxide as the oxidant in a methanol and water solution was studied. Aryl nitriles were converted to aryl amides with very high selectivity of 95%～100% at room temperature. The reactivity of aryl nitriles decreased with increasing their branched chain length. In the oxidation of tolunitriles, the oxidation rate of p-tolunitrile and m-tolunitrile was very fast, but the oxidation rate of o-tolunitrile was very slow. The oxidation rate of p-haloid aryl nitriles and p-nitro aryl nitrile decreased in the order p-nitrobenzonitrile >p-chlorobenzonitrile>p-bromobenzonitrile, while the selectivity for aryl amides was maintained at a high level of 98%～100%. The comparison of the two oxidants showed that when sodium carbonate-hydrogen peroxide was used as oxidant, the oxidation rate and selectivity were better than that when percarbonate was used. The sodium tungstate catalyst and carbonate can be reused and the catalytic activity and selectivity did not change if a suitable amount of hydrogen peroxide was supplied. This work provides a convenient method for the preparation of aryl amides from aryl nitriles under very mild reaction conditions.
