Sulfamic acid has been used as an efficient catalyst and green alternative for conventional acidic materials to promote the acetolysis reaction of THF to produce 1, 4-diacetoxybutane. This method is also applicable in...Sulfamic acid has been used as an efficient catalyst and green alternative for conventional acidic materials to promote the acetolysis reaction of THF to produce 1, 4-diacetoxybutane. This method is also applicable in the acetolysis of other cyclic ethers, such as methyl substituted THF and tetrahydropyran and 1,4-dioxane which is less reactivity.展开更多
Three chiral aminopyridine ligands derived from L-proline were prepared. Careful evaluation of the corresponding aminopyridine manganese complexes in asymmetric epoxidation of olefins revealed a broad substrate scope ...Three chiral aminopyridine ligands derived from L-proline were prepared. Careful evaluation of the corresponding aminopyridine manganese complexes in asymmetric epoxidation of olefins revealed a broad substrate scope in the presence of 0.2 mol% manganese complex and 0.5 equiv. 2,2-dimethylbutyric acid, with aqueous hydrogen peroxide as an oxidant. A variety of olefins including styrenes, chromenes, and cinnamamides were transformed successfully into the target epoxides with moderate to excellent enantioselectivity（yield up to 95%, ee up to 99%）.展开更多
The conversion and utilization of natural gas is of significant meaning to the national economy, even to the everyday life of people. However, it has not become a popular industrial process as expected due to the tech...The conversion and utilization of natural gas is of significant meaning to the national economy, even to the everyday life of people. However, it has not become a popular industrial process as expected due to the technical obstacles. In the past decades, much investigation into the conversion of methane, predominant component of natural gas, has been carried out. Among the possible routes, of methane conversion, the partial oxidation of methane to synthesis gas is considered as an effective and economically feasible one. In this article, a brief review of recent studies on the mechanism of the partial oxidation of methane to synthesis gas together with catalyst development is wherein presented.展开更多
Tabular PE PbTiO 3, spherical PY PbTiO 3, and acicular PX PbTiO 3 powders were hydrothermally synthesized from triethanolamine(TEA) complexed precursor; clubbed PE PbTiO 3 powders were obtained from diethanol...Tabular PE PbTiO 3, spherical PY PbTiO 3, and acicular PX PbTiO 3 powders were hydrothermally synthesized from triethanolamine(TEA) complexed precursor; clubbed PE PbTiO 3 powders were obtained from diethanolamine(DEA) complexed precursor. The effects of pH of the hydrolyzation as well as complexing agents including TEA, DEA, and MEA(monoethanolamine) on the structure and the morphology of PbTiO 3 powders are discussed. The optimal conditions for hydrothermal syntheses of acicular and clubbed PbTiO 3 powders have been established. The products were characterized by means of XRD, TEM and other techniques.展开更多
A mild and efficient oxidation of alcohols to the corresponding carbonyl compounds using the PhI(OAc)2 (1.1 eq.) with n-Bu4NBr (8 mol %) in water at room temperature is described. This new procedure is very simple and...A mild and efficient oxidation of alcohols to the corresponding carbonyl compounds using the PhI(OAc)2 (1.1 eq.) with n-Bu4NBr (8 mol %) in water at room temperature is described. This new procedure is very simple and affords the desired carbonyl compounds in high yields.展开更多
Enantioselective conjugate addition of diethylzinc to chalcone was carried out in the presence of Ni(acac) 2 complexed with five pyrrolidinylmethanols derived from L proline. ( S ) N Benzyl 2 (1 hydro...Enantioselective conjugate addition of diethylzinc to chalcone was carried out in the presence of Ni(acac) 2 complexed with five pyrrolidinylmethanols derived from L proline. ( S ) N Benzyl 2 (1 hydroxy 1 methylethyl) pyrrolidine was found to be the best ligand in asymmetric conjugate addition among the five ligands. The products were obtained with up to 70% ee . The configuration of the product was determined jointly by the substituents on the carbon of the hydroxy group and the nitrogen atom.展开更多
The new chiral cluster [NiRuMo(CO)5(m3-S)(h5-C5H5)(h5-C5H4COCH3)] 3 was synthesized by the reaction of precursor [CoRuMo(CO)8(m3-S)(h5-C5H4COCH3)] 1 with NiCp2 2 in refluxing THF. It was characterized by C/H elemental...The new chiral cluster [NiRuMo(CO)5(m3-S)(h5-C5H5)(h5-C5H4COCH3)] 3 was synthesized by the reaction of precursor [CoRuMo(CO)8(m3-S)(h5-C5H4COCH3)] 1 with NiCp2 2 in refluxing THF. It was characterized by C/H elemental analysis, IR and 1H NMR. Molecular structure of cluster 3 was determined by single-crystal X-ray analyses. Crystal data: triclinic, space group P with the following crystallographic parameters: a = 7.9606(8), b = 8.5604(9), c = 14.779(2) , a = 93.908(2), b = 105.057(2), g = 101.463(2)? C17H12O6MoNiRuS, Mr = 600.05, Z = 2, V = 945.5(2) 3, Dc = 2.108 g/cm3, m = 2.568 mm-1, (2q )max ≤ 56.48, F(000) = 584,the final R = 0.0380 and wR = 0.0674 for 2995 observed reflections with I > 2.00s(I).展开更多
文摘Sulfamic acid has been used as an efficient catalyst and green alternative for conventional acidic materials to promote the acetolysis reaction of THF to produce 1, 4-diacetoxybutane. This method is also applicable in the acetolysis of other cyclic ethers, such as methyl substituted THF and tetrahydropyran and 1,4-dioxane which is less reactivity.
基金supported by the National Natural Science Foundation of China(21473226,21773273)Key Research Program of Frontier Sciences,CAS(QYZDJ-SSW-SLH051)Natural Science Foundation of Jiangsu Province(BK20170420)~~
文摘Three chiral aminopyridine ligands derived from L-proline were prepared. Careful evaluation of the corresponding aminopyridine manganese complexes in asymmetric epoxidation of olefins revealed a broad substrate scope in the presence of 0.2 mol% manganese complex and 0.5 equiv. 2,2-dimethylbutyric acid, with aqueous hydrogen peroxide as an oxidant. A variety of olefins including styrenes, chromenes, and cinnamamides were transformed successfully into the target epoxides with moderate to excellent enantioselectivity（yield up to 95%, ee up to 99%）.
文摘The conversion and utilization of natural gas is of significant meaning to the national economy, even to the everyday life of people. However, it has not become a popular industrial process as expected due to the technical obstacles. In the past decades, much investigation into the conversion of methane, predominant component of natural gas, has been carried out. Among the possible routes, of methane conversion, the partial oxidation of methane to synthesis gas is considered as an effective and economically feasible one. In this article, a brief review of recent studies on the mechanism of the partial oxidation of methane to synthesis gas together with catalyst development is wherein presented.
文摘Tabular PE PbTiO 3, spherical PY PbTiO 3, and acicular PX PbTiO 3 powders were hydrothermally synthesized from triethanolamine(TEA) complexed precursor; clubbed PE PbTiO 3 powders were obtained from diethanolamine(DEA) complexed precursor. The effects of pH of the hydrolyzation as well as complexing agents including TEA, DEA, and MEA(monoethanolamine) on the structure and the morphology of PbTiO 3 powders are discussed. The optimal conditions for hydrothermal syntheses of acicular and clubbed PbTiO 3 powders have been established. The products were characterized by means of XRD, TEM and other techniques.
文摘A mild and efficient oxidation of alcohols to the corresponding carbonyl compounds using the PhI(OAc)2 (1.1 eq.) with n-Bu4NBr (8 mol %) in water at room temperature is described. This new procedure is very simple and affords the desired carbonyl compounds in high yields.
基金theNationalNaturalScienceFoundationofChina (No .2 9972 0 16andQTProgram ) theTeachingandResearchAwardProgramforOutstandingYoungTeachersinHigherEducationInstitutionsoftheMinistryofEducationofChina
文摘Enantioselective conjugate addition of diethylzinc to chalcone was carried out in the presence of Ni(acac) 2 complexed with five pyrrolidinylmethanols derived from L proline. ( S ) N Benzyl 2 (1 hydroxy 1 methylethyl) pyrrolidine was found to be the best ligand in asymmetric conjugate addition among the five ligands. The products were obtained with up to 70% ee . The configuration of the product was determined jointly by the substituents on the carbon of the hydroxy group and the nitrogen atom.
基金This work was supported by the National Natural Science Foundation of China(29871061)
文摘The new chiral cluster [NiRuMo(CO)5(m3-S)(h5-C5H5)(h5-C5H4COCH3)] 3 was synthesized by the reaction of precursor [CoRuMo(CO)8(m3-S)(h5-C5H4COCH3)] 1 with NiCp2 2 in refluxing THF. It was characterized by C/H elemental analysis, IR and 1H NMR. Molecular structure of cluster 3 was determined by single-crystal X-ray analyses. Crystal data: triclinic, space group P with the following crystallographic parameters: a = 7.9606(8), b = 8.5604(9), c = 14.779(2) , a = 93.908(2), b = 105.057(2), g = 101.463(2)? C17H12O6MoNiRuS, Mr = 600.05, Z = 2, V = 945.5(2) 3, Dc = 2.108 g/cm3, m = 2.568 mm-1, (2q )max ≤ 56.48, F(000) = 584,the final R = 0.0380 and wR = 0.0674 for 2995 observed reflections with I > 2.00s(I).
