The interfering kinetics of the coherent synchronous reactions of hydrogen peroxide decomposition and the oxidation of pyridine derivatives have been studied experimentally. The regions of the selective oxidation of t...The interfering kinetics of the coherent synchronous reactions of hydrogen peroxide decomposition and the oxidation of pyridine derivatives have been studied experimentally. The regions of the selective oxidation of the pyridine derivatives have been found, and the optimal conditions for the production of4-vynilpyridine, 4-vynilpyridine N-monoxide, 2, 2-dipyridyl, and pyridine have been determined. The most probable synchronization mechanism is suggested for hydrogen peroxide decomposition and the free-radical chain oxidation of pyridine derivatives. The HO2 -radical plays the key role in this mechanism. The activation energies are calculated for the elementary steps of 4-ethylpyridine dehydrogenation.展开更多
The crystal structure of the title compound (C16H17NO5) has been determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group C2/c with a = 18.520(2), b = 7.8910(1), c = 21.728(3) A, β = ...The crystal structure of the title compound (C16H17NO5) has been determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group C2/c with a = 18.520(2), b = 7.8910(1), c = 21.728(3) A, β = 104.77(1)°, V= 3070.4(7) A3, Mr= 303.31, Z = 8, Dc= 1.312 g/cm3, λ = 0.71073 A,μ(MoKα) = 0.098 mm-1 and F(000) = 1280. The structure was refined to R = 0.0486 and wR = 0.1287. There exist intermolecular hydrogen bonds in the crystal.展开更多
Three stable 4-substituted pyridine-based ruthenium（II）complexes[RuCl2（PPh3）L]（L=4-R-2,6-bis （diethylaminomethylene）pyridine,R=Br,H or allyloxy）were synthesized.The catalytic activities of the complexes toward...Three stable 4-substituted pyridine-based ruthenium（II）complexes[RuCl2（PPh3）L]（L=4-R-2,6-bis （diethylaminomethylene）pyridine,R=Br,H or allyloxy）were synthesized.The catalytic activities of the complexes toward transfer hydrogenation from alcohols to ketones were investigated.The electronic effects of the para-substituent in the pyridyl ring were probed and we found that the electron-donating group increased the catalytic activity.The result suggests that an electron-donating group is probably preferential for linking the catalytic ruthenium complex and the chemically inert supporting molecules such as a carbosilane dendrimer.展开更多
Three ruthenium(II)complex catalysts bearing2,6‐bis(tetrazolyl)pyridine were synthesized,structurally characterized,and applied in the transfer hydrogenation of ketones.Their different catalytic activities were attri...Three ruthenium(II)complex catalysts bearing2,6‐bis(tetrazolyl)pyridine were synthesized,structurally characterized,and applied in the transfer hydrogenation of ketones.Their different catalytic activities were attributed to the different phosphine ligands on the4‐chloro‐2,6‐bis(1‐(p‐tolyl)‐1Htetrazol‐5‐yl)pyridine ruthenium(II)complexes,with that based on1,4‐bis(diphenylphosphino)butane exhibiting better catalytic activity.A variety of ketones were reduced to their corresponding alcohols with>95%conversion.展开更多
Piperidine-4-ones and tetrahydropyrane-4-ones are important precursors for the synthesis of functionally substituted piperidines and tetrahydropyranes. In this study, the condensation of hexa-2, 4-diene and 2-methyl-p...Piperidine-4-ones and tetrahydropyrane-4-ones are important precursors for the synthesis of functionally substituted piperidines and tetrahydropyranes. In this study, the condensation of hexa-2, 4-diene and 2-methyl-penta-2, 4-diene with formaldehyde （reaction of oxymethylation） was investigated. The functionally substituted derivatives of piperidine and tetrahydropyrane were synthesized. The comparison of oxymethylation of dienes and 1-alkenes was showed, which indicates that the highest yield of tetrahydropyrane derivatives was achieved with 1-alkenes. This study provided theoretical basis for the synthesis of piperidine and tetrahydropyrane derivatives.展开更多
The reaction between [Ru3(3-O)(-CH3CO2)6(py)2(MeOH)](PF6) (py = pyri- dine) and diphenyl-2-pyridyl-phosphine (PPh2py) gave the triruthenium cluster complex [RuIII3(3-O)(-CH3CO2)6(py)2(PPh2py)](PF6)CH2Cl2 (C40H44Cl2F6N...The reaction between [Ru3(3-O)(-CH3CO2)6(py)2(MeOH)](PF6) (py = pyri- dine) and diphenyl-2-pyridyl-phosphine (PPh2py) gave the triruthenium cluster complex [RuIII3(3-O)(-CH3CO2)6(py)2(PPh2py)](PF6)CH2Cl2 (C40H44Cl2F6N34O13P2Ru3) which was characterized by elemental analysis, IR, UV-Vis and 31P NMR spectroscopy, and X-ray single- crystal diffraction. The structure is of monoclinic, space group P21/n with a = 16.3896(1), b = 16.8773(2), c = 19.1438(2) ? b = 95.888(1), V = 5267.47(9) ?, Mr = 1324.83, Dc = 1.671 g/cm3, F(000) = 2636, m = 1.092 mm-1 and Z = 4. The final refinement gave R = 0.0508 and wR = 0.1111 for 6987 observed reflections (I > 2s(I)). Three Ru(III) atoms bridged by m3-oxo donor form an approximately isosceles triangle. The complex shows three quasireversible one- electron processes at E1/2 = 1.22 +0.03 and 1.20 V vs. Ag/AgCl.展开更多
The regions of the selective oxidation of the the production of 4-vinylpyridine, 4-vinylpyridine coherent-synchronized mechanism is suggested for 4-ethylpyridine and piperidine. The HO^＊2 radical plays 4-ethylpyridin...The regions of the selective oxidation of the the production of 4-vinylpyridine, 4-vinylpyridine coherent-synchronized mechanism is suggested for 4-ethylpyridine and piperidine. The HO^＊2 radical plays 4-ethylpyridine and piperidine have been found, and the optimal conditions for N-monoxide and pyridine have been determined. The most probable hydrogen peroxide decomposition and the free-radical chain oxidation of the key role in this mechanism.展开更多
文摘The interfering kinetics of the coherent synchronous reactions of hydrogen peroxide decomposition and the oxidation of pyridine derivatives have been studied experimentally. The regions of the selective oxidation of the pyridine derivatives have been found, and the optimal conditions for the production of4-vynilpyridine, 4-vynilpyridine N-monoxide, 2, 2-dipyridyl, and pyridine have been determined. The most probable synchronization mechanism is suggested for hydrogen peroxide decomposition and the free-radical chain oxidation of pyridine derivatives. The HO2 -radical plays the key role in this mechanism. The activation energies are calculated for the elementary steps of 4-ethylpyridine dehydrogenation.
基金Supported by the Natural Science Foundation of Jiangsu province(No.BK2001142)the Natural Science Foundation of Jiangsu Education Department(No.01KJB150008)
文摘The crystal structure of the title compound (C16H17NO5) has been determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group C2/c with a = 18.520(2), b = 7.8910(1), c = 21.728(3) A, β = 104.77(1)°, V= 3070.4(7) A3, Mr= 303.31, Z = 8, Dc= 1.312 g/cm3, λ = 0.71073 A,μ(MoKα) = 0.098 mm-1 and F(000) = 1280. The structure was refined to R = 0.0486 and wR = 0.1287. There exist intermolecular hydrogen bonds in the crystal.
基金Supported by the National Natural Science Foundation of China（20576052） the Joint Innovation Fund of Jiangsu Province（BY2009107） the National Basic Research Program of China（2003CB615707）
文摘Three stable 4-substituted pyridine-based ruthenium（II）complexes[RuCl2（PPh3）L]（L=4-R-2,6-bis （diethylaminomethylene）pyridine,R=Br,H or allyloxy）were synthesized.The catalytic activities of the complexes toward transfer hydrogenation from alcohols to ketones were investigated.The electronic effects of the para-substituent in the pyridyl ring were probed and we found that the electron-donating group increased the catalytic activity.The result suggests that an electron-donating group is probably preferential for linking the catalytic ruthenium complex and the chemically inert supporting molecules such as a carbosilane dendrimer.
文摘Three ruthenium(II)complex catalysts bearing2,6‐bis(tetrazolyl)pyridine were synthesized,structurally characterized,and applied in the transfer hydrogenation of ketones.Their different catalytic activities were attributed to the different phosphine ligands on the4‐chloro‐2,6‐bis(1‐(p‐tolyl)‐1Htetrazol‐5‐yl)pyridine ruthenium(II)complexes,with that based on1,4‐bis(diphenylphosphino)butane exhibiting better catalytic activity.A variety of ketones were reduced to their corresponding alcohols with>95%conversion.
文摘Piperidine-4-ones and tetrahydropyrane-4-ones are important precursors for the synthesis of functionally substituted piperidines and tetrahydropyranes. In this study, the condensation of hexa-2, 4-diene and 2-methyl-penta-2, 4-diene with formaldehyde （reaction of oxymethylation） was investigated. The functionally substituted derivatives of piperidine and tetrahydropyrane were synthesized. The comparison of oxymethylation of dienes and 1-alkenes was showed, which indicates that the highest yield of tetrahydropyrane derivatives was achieved with 1-alkenes. This study provided theoretical basis for the synthesis of piperidine and tetrahydropyrane derivatives.
基金This work was supported by NNSFC and NSF of Fujian Province
文摘The reaction between [Ru3(3-O)(-CH3CO2)6(py)2(MeOH)](PF6) (py = pyri- dine) and diphenyl-2-pyridyl-phosphine (PPh2py) gave the triruthenium cluster complex [RuIII3(3-O)(-CH3CO2)6(py)2(PPh2py)](PF6)CH2Cl2 (C40H44Cl2F6N34O13P2Ru3) which was characterized by elemental analysis, IR, UV-Vis and 31P NMR spectroscopy, and X-ray single- crystal diffraction. The structure is of monoclinic, space group P21/n with a = 16.3896(1), b = 16.8773(2), c = 19.1438(2) ? b = 95.888(1), V = 5267.47(9) ?, Mr = 1324.83, Dc = 1.671 g/cm3, F(000) = 2636, m = 1.092 mm-1 and Z = 4. The final refinement gave R = 0.0508 and wR = 0.1111 for 6987 observed reflections (I > 2s(I)). Three Ru(III) atoms bridged by m3-oxo donor form an approximately isosceles triangle. The complex shows three quasireversible one- electron processes at E1/2 = 1.22 +0.03 and 1.20 V vs. Ag/AgCl.
文摘The regions of the selective oxidation of the the production of 4-vinylpyridine, 4-vinylpyridine coherent-synchronized mechanism is suggested for 4-ethylpyridine and piperidine. The HO^＊2 radical plays 4-ethylpyridine and piperidine have been found, and the optimal conditions for N-monoxide and pyridine have been determined. The most probable hydrogen peroxide decomposition and the free-radical chain oxidation of the key role in this mechanism.
