Rh nanoparticles stabilized by PEG-substituted triphenyl-phosphine（PETPP,P[C6H4-p-（OCH2CH2）nOH]3） combining double stabilization effects demonstrated high activity and good recyclability in aqueous biphasic hydrog...Rh nanoparticles stabilized by PEG-substituted triphenyl-phosphine（PETPP,P[C6H4-p-（OCH2CH2）nOH]3） combining double stabilization effects demonstrated high activity and good recyclability in aqueous biphasic hydrogenation of benzene.The value of turnover frequency（TOF） was 3333 h^-1.Furthermore,the rhodium nanoparticle catalyst could be easily recycled for five times without loss in activity.展开更多
Polyether-tailored phosphite modified rhodium complex formed in situ was highly active in the hydroformylation of oleyl alcohol in nonaqueous phosphite/heptane system where the phosphite acted both as the ligand and t...Polyether-tailored phosphite modified rhodium complex formed in situ was highly active in the hydroformylation of oleyl alcohol in nonaqueous phosphite/heptane system where the phosphite acted both as the ligand and the second phase. This catalyst was easily separated by simple decantation and can be used for five times with only a slight decrease in activity.展开更多
A new thermomorphic catalytic system for the Baylis-Hillman coupling of aromatic aldehydes with a, β-unsaturated ketone has been described, in which the alkyl-functionalized dendritic catalyst preferred to dissolve i...A new thermomorphic catalytic system for the Baylis-Hillman coupling of aromatic aldehydes with a, β-unsaturated ketone has been described, in which the alkyl-functionalized dendritic catalyst preferred to dissolve in non-polar organic layer in the thermomorphic biphasic system, leading to easy separation of the catalyst from the polar products by changing the temperature of the system at end of the reaction.展开更多
The complex [Rh（CO）（Pz）（TPPMS）]2, （TPPMS = m-sulfonatophenyl-diphenylphosphine, Pz = Pirazolate） was evaluated as a catalyst precursor in the hydroformylation of allylbenzenes （eugenol and estragol） and terp...The complex [Rh（CO）（Pz）（TPPMS）]2, （TPPMS = m-sulfonatophenyl-diphenylphosphine, Pz = Pirazolate） was evaluated as a catalyst precursor in the hydroformylation of allylbenzenes （eugenol and estragol） and terpenes （limonene and myrcene） and in the hydrogenation of α,β-unsaturated aldehydes （crotonaldehyde, cinnamaldehyde and citral） in a biphasic medium toluene/ionic liquid. Under the reaction conditions studied （P = 600 psi, T= 95 ℃, S/C = 300：1）, the rhodium system showed a high activity and selectivity towards the desired aldehydes. The catalytic phase could be recycled up to five times without any evident loss of activity or selectivity.展开更多
THE oxidative dehydrogenation of propane （ODP） to propene is one of the potentially important catalytic processes for the effective utilization of light alkanes. The VMgO catalysts which have better catalytic perfor...THE oxidative dehydrogenation of propane （ODP） to propene is one of the potentially important catalytic processes for the effective utilization of light alkanes. The VMgO catalysts which have better catalytic performances for the reaction have aroused much interest and argument.Kung et al. proposed that the active phase was magnesium orthovanadate （Mg<sub>3</sub>V<sub>2</sub>O<sub>8</sub>）, but Volta et al. suggested that magnesium pyrovanadate （α-Mg<sub>2</sub>V<sub>2</sub>O<sub>7</sub>） was the active phase; in this phase, V<sup>4+</sup> ions which are associated to the formation of oxygen vacancies could stably exist, and Mg<sub>3</sub>V<sub>2</sub>O<sub>8</sub> is responsible for the total oxidation due to nonexistence of V<sup>4+</sup> ions.展开更多
Palladium nanoparticles immobilized on a cross-linked imidazolium-containing polymer were evaluated as a catalyst for Suzuki carbon-carbon cross-coupling reactions using water as the solvent. The nanocatalysts show go...Palladium nanoparticles immobilized on a cross-linked imidazolium-containing polymer were evaluated as a catalyst for Suzuki carbon-carbon cross-coupling reactions using water as the solvent. The nanocatalysts show good catalytic activities for aryl iodides and aryl bromides and moderate activity with aryl chloride substrates. Coupling of sterically hindered substrates could also be achieved in reasonable yields. The heterogeneous catalyst is stable, can be stored without precautions to exclude air or moisture, and can be easily recycled and reused.展开更多
基金support from the National Natural Science Foundation of China(No.20573015)the Program for New Century Excellent Talents in University(No.NCET-07-0138)the Science and Technology Project in Universities from the Education Department of Liaoning Province(No.2008T233)
文摘Rh nanoparticles stabilized by PEG-substituted triphenyl-phosphine（PETPP,P[C6H4-p-（OCH2CH2）nOH]3） combining double stabilization effects demonstrated high activity and good recyclability in aqueous biphasic hydrogenation of benzene.The value of turnover frequency（TOF） was 3333 h^-1.Furthermore,the rhodium nanoparticle catalyst could be easily recycled for five times without loss in activity.
基金The authors are grateful to the financial support from the National Natural Science Foundation of China(Grant No.29906001)
文摘Polyether-tailored phosphite modified rhodium complex formed in situ was highly active in the hydroformylation of oleyl alcohol in nonaqueous phosphite/heptane system where the phosphite acted both as the ligand and the second phase. This catalyst was easily separated by simple decantation and can be used for five times with only a slight decrease in activity.
文摘A new thermomorphic catalytic system for the Baylis-Hillman coupling of aromatic aldehydes with a, β-unsaturated ketone has been described, in which the alkyl-functionalized dendritic catalyst preferred to dissolve in non-polar organic layer in the thermomorphic biphasic system, leading to easy separation of the catalyst from the polar products by changing the temperature of the system at end of the reaction.
文摘The complex [Rh（CO）（Pz）（TPPMS）]2, （TPPMS = m-sulfonatophenyl-diphenylphosphine, Pz = Pirazolate） was evaluated as a catalyst precursor in the hydroformylation of allylbenzenes （eugenol and estragol） and terpenes （limonene and myrcene） and in the hydrogenation of α,β-unsaturated aldehydes （crotonaldehyde, cinnamaldehyde and citral） in a biphasic medium toluene/ionic liquid. Under the reaction conditions studied （P = 600 psi, T= 95 ℃, S/C = 300：1）, the rhodium system showed a high activity and selectivity towards the desired aldehydes. The catalytic phase could be recycled up to five times without any evident loss of activity or selectivity.
文摘THE oxidative dehydrogenation of propane （ODP） to propene is one of the potentially important catalytic processes for the effective utilization of light alkanes. The VMgO catalysts which have better catalytic performances for the reaction have aroused much interest and argument.Kung et al. proposed that the active phase was magnesium orthovanadate （Mg<sub>3</sub>V<sub>2</sub>O<sub>8</sub>）, but Volta et al. suggested that magnesium pyrovanadate （α-Mg<sub>2</sub>V<sub>2</sub>O<sub>7</sub>） was the active phase; in this phase, V<sup>4+</sup> ions which are associated to the formation of oxygen vacancies could stably exist, and Mg<sub>3</sub>V<sub>2</sub>O<sub>8</sub> is responsible for the total oxidation due to nonexistence of V<sup>4+</sup> ions.
基金supported by the Ecole Polytechnique Fédérale de Lausanne and the Iranian Ministry of Science,Research and Technology(to S.G.-E.)
文摘Palladium nanoparticles immobilized on a cross-linked imidazolium-containing polymer were evaluated as a catalyst for Suzuki carbon-carbon cross-coupling reactions using water as the solvent. The nanocatalysts show good catalytic activities for aryl iodides and aryl bromides and moderate activity with aryl chloride substrates. Coupling of sterically hindered substrates could also be achieved in reasonable yields. The heterogeneous catalyst is stable, can be stored without precautions to exclude air or moisture, and can be easily recycled and reused.
