At 200 ℃ and 50 mPa, the oxidative carbonylation of amines catalyzed by organic gold complexes HAuCl 4, Au(PPh 3)Cl, Au(PPh 3) 2Cl, Au(PPh 3)NO 3 and [Au(PPh 3)] 2S afforded R(NHCO 2CH 3) n with a high conversion and...At 200 ℃ and 50 mPa, the oxidative carbonylation of amines catalyzed by organic gold complexes HAuCl 4, Au(PPh 3)Cl, Au(PPh 3) 2Cl, Au(PPh 3)NO 3 and [Au(PPh 3)] 2S afforded R(NHCO 2CH 3) n with a high conversion and selectivity. The best results were obtained when using the catalyst Au(PPh 3)Cl in the presence of PPh 3. The catalytic efficiency of catalytic Au(PPh 3)Cl was compared to Pd(PPh 3) 2Cl 2, e.g. the conversion was 97.2% and selectivity was 89% when using catalyst Au(PPh 3)Cl in the presence of PPh 3, while the conversion was 98.8% and selectivity was 86% when using catalyst Pd(PPh 3) 2Cl 2 in the presence of PPh 3. The experimental results suggested that Au complexes might be promising catalysts instead of Pd catalysts for the oxidative carbonylation of amines to carbamates.展开更多
A facile and user friendly technique to immobilize the late-transition metal complexes on spherical MgCl2/SiO2/THF support has been developed. The spherical MgCl2/SiO2/THF-supported late-transition metal catalysts 2,6...A facile and user friendly technique to immobilize the late-transition metal complexes on spherical MgCl2/SiO2/THF support has been developed. The spherical MgCl2/SiO2/THF-supported late-transition metal catalysts 2,6-bis-[1-(2,6-dimethylphenylimino)ethyl]pyridine iron(II) dichloride(SC-A) and 1,4-bis(2,6-dimethylphenyl)- acenaphthene diimine nickel(II) dibromide(SC-B) for ethylene polymerization has been prepared by spray-drying technique using tetrahydrofuran suspension containing MgCl2, SiO2 and late-transition metal complexes. The catalysts were characterized by BET, XRD, SEM and the polymers were analyzed using GPC, DSC and 13C-NMR. The test results show that spray-drying is a very effective method for immobilizing late-transition metal catalysts for ethylene polymerization. Among six kinds of cocatalysts for olefin polymerization, TMA and TEA were confirmed to be more effective than other compounds for the ethylene polymerization system using the catalyst SC-A. For the case of the catalyst SC-B, DEAC showed the best performance as cocatalysts in ethylene polymerization. The replication of the catalyst morphology was found in the resultant polyethylene.展开更多
文摘At 200 ℃ and 50 mPa, the oxidative carbonylation of amines catalyzed by organic gold complexes HAuCl 4, Au(PPh 3)Cl, Au(PPh 3) 2Cl, Au(PPh 3)NO 3 and [Au(PPh 3)] 2S afforded R(NHCO 2CH 3) n with a high conversion and selectivity. The best results were obtained when using the catalyst Au(PPh 3)Cl in the presence of PPh 3. The catalytic efficiency of catalytic Au(PPh 3)Cl was compared to Pd(PPh 3) 2Cl 2, e.g. the conversion was 97.2% and selectivity was 89% when using catalyst Au(PPh 3)Cl in the presence of PPh 3, while the conversion was 98.8% and selectivity was 86% when using catalyst Pd(PPh 3) 2Cl 2 in the presence of PPh 3. The experimental results suggested that Au complexes might be promising catalysts instead of Pd catalysts for the oxidative carbonylation of amines to carbamates.
基金supported by the Scientific Foundation of Education Department in Yunnan Province, China (07Z11621)Innovation Foundationfor New Researchers in Dali University, China (KY421040)~~
基金supported by the National Natural Science Foundation of China (Grant No.U1162114)the Science Foundation of Tianjin University of Science & Technology (20090420)
文摘A facile and user friendly technique to immobilize the late-transition metal complexes on spherical MgCl2/SiO2/THF support has been developed. The spherical MgCl2/SiO2/THF-supported late-transition metal catalysts 2,6-bis-[1-(2,6-dimethylphenylimino)ethyl]pyridine iron(II) dichloride(SC-A) and 1,4-bis(2,6-dimethylphenyl)- acenaphthene diimine nickel(II) dibromide(SC-B) for ethylene polymerization has been prepared by spray-drying technique using tetrahydrofuran suspension containing MgCl2, SiO2 and late-transition metal complexes. The catalysts were characterized by BET, XRD, SEM and the polymers were analyzed using GPC, DSC and 13C-NMR. The test results show that spray-drying is a very effective method for immobilizing late-transition metal catalysts for ethylene polymerization. Among six kinds of cocatalysts for olefin polymerization, TMA and TEA were confirmed to be more effective than other compounds for the ethylene polymerization system using the catalyst SC-A. For the case of the catalyst SC-B, DEAC showed the best performance as cocatalysts in ethylene polymerization. The replication of the catalyst morphology was found in the resultant polyethylene.
