The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Mark M. Turnbull - One of the best experts on this subject based on the ideXlab platform.
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Well-isolated pyrazine-bridged copper(II) chains: synthesis and magneto-structural analysis
Journal of Coordination Chemistry, 2020Co-Authors: Jeffrey C. Monroe, Christopher P. Landee, Mark M. Turnbull, Jan L. WikairaAbstract:A pair of well-isolated 1-D-QHAF compounds with the molecular formula [Cu(pz)(L)2(H2O)2](ClO4)2 with L = 3-Cl-4-Hydroxypyridine (1) and 3-Br-4-Hydroxypyridine (2) (catena-(diaqua-bis(3-chloro/bromo...
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Unusual coordination behavior by a hydroxypyridine/pyridone ligand: Synthesis and structure of [(2-bromo-4-Hydroxypyridine)2(2-bromo-1(H)-4-pyridone)2copper(II)] perchlorate • 2(2-bromo-4-Hydroxypyridine) • 2(2-bromo-1(H)-4-pyridone)
Journal of Coordination Chemistry, 2019Co-Authors: Jeffrey C. Monroe, Mark M. TurnbullAbstract:AbstractThe synthesis and structure of [Cu(2-Br-4-HOpy)2(2-Br-4-pyone)2](ClO4)2 • 2(2-Br-4-HOpy) • 2(2-Br-4-pyone) is reported [2-Br-4-HOpy = 2-bromo-4-Hydroxypyridine; 2-Br-4-pyone = 2-bromo-(1H)4...
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CRYSTAL STRUCTURE OF 2-BROMO-4-Hydroxypyridine: HYDROGEN AND HALOGEN BONDING
European Chemical Bulletin, 2019Co-Authors: Jeffrey C. Monroe, Mark M. TurnbullAbstract:The crystal structure of 2-bromo-4-Hydroxypyridine (1 )at 120 K is reported. The compound crystallizes in the monoclinic space group C 2/c with a = 15.6770(6) A, b = 3.86471(13) A, c = 18.0645(7) A and β = 90.916(3)°. The compound exhibits both the 4-Hydroxypyridine and 4-pyridone tautomers as exhibited by the disordered proton which occupies the O-H and N-H positions equally. Hydrogen bonding links the molecules into chains parallel to the ac -face diagonal. Halogen bonds [Br … O = 3.0809(15) A] roughly parallel to the a -axis link the chains into layers roughly parallel to the bc -face diagonal. π-stacking interactions complete the stabilization of the structure.
Jeffrey C. Monroe - One of the best experts on this subject based on the ideXlab platform.
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Well-isolated pyrazine-bridged copper(II) chains: synthesis and magneto-structural analysis
Journal of Coordination Chemistry, 2020Co-Authors: Jeffrey C. Monroe, Christopher P. Landee, Mark M. Turnbull, Jan L. WikairaAbstract:A pair of well-isolated 1-D-QHAF compounds with the molecular formula [Cu(pz)(L)2(H2O)2](ClO4)2 with L = 3-Cl-4-Hydroxypyridine (1) and 3-Br-4-Hydroxypyridine (2) (catena-(diaqua-bis(3-chloro/bromo...
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Unusual coordination behavior by a hydroxypyridine/pyridone ligand: Synthesis and structure of [(2-bromo-4-Hydroxypyridine)2(2-bromo-1(H)-4-pyridone)2copper(II)] perchlorate • 2(2-bromo-4-Hydroxypyridine) • 2(2-bromo-1(H)-4-pyridone)
Journal of Coordination Chemistry, 2019Co-Authors: Jeffrey C. Monroe, Mark M. TurnbullAbstract:AbstractThe synthesis and structure of [Cu(2-Br-4-HOpy)2(2-Br-4-pyone)2](ClO4)2 • 2(2-Br-4-HOpy) • 2(2-Br-4-pyone) is reported [2-Br-4-HOpy = 2-bromo-4-Hydroxypyridine; 2-Br-4-pyone = 2-bromo-(1H)4...
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CRYSTAL STRUCTURE OF 2-BROMO-4-Hydroxypyridine: HYDROGEN AND HALOGEN BONDING
European Chemical Bulletin, 2019Co-Authors: Jeffrey C. Monroe, Mark M. TurnbullAbstract:The crystal structure of 2-bromo-4-Hydroxypyridine (1 )at 120 K is reported. The compound crystallizes in the monoclinic space group C 2/c with a = 15.6770(6) A, b = 3.86471(13) A, c = 18.0645(7) A and β = 90.916(3)°. The compound exhibits both the 4-Hydroxypyridine and 4-pyridone tautomers as exhibited by the disordered proton which occupies the O-H and N-H positions equally. Hydrogen bonding links the molecules into chains parallel to the ac -face diagonal. Halogen bonds [Br … O = 3.0809(15) A] roughly parallel to the a -axis link the chains into layers roughly parallel to the bc -face diagonal. π-stacking interactions complete the stabilization of the structure.
Hans-ulrich Reissig - One of the best experts on this subject based on the ideXlab platform.
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Four-Component Synthesis of Functionalized 2,2′-Bipyridines Based on the Blaise Reaction
ChemInform, 2012Co-Authors: Paul Hommes, Phillip Jungk, Hans-ulrich ReissigAbstract:E/Z-Mixtures of N-acylated-β-ketoamides are prepared from the corresponding nitriles and used as efficient precursors for the TmsOTf-promoted cyclization to 4-Hydroxypyridine derivatives.
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A practical two-step procedure for the preparation of enantiopure pyridines: Multicomponent reactions of alkoxyallenes, nitriles and carboxylic acids followed by a cyclocondensation reaction.
Beilstein journal of organic chemistry, 2011Co-Authors: Christian Eidamshaus, Roopender Kumar, Mrinal K. Bera, Hans-ulrich ReissigAbstract:A practical approach to highly functionalized 4-Hydroxypyridine derivatives with stereogenic side chains in the 2- and 6-positions is described. The presented two-step process utilizes a multicomponent reaction of alkoxyallenes, nitriles and carboxylic acids to provide β-methoxy-β-ketoenamides which are transformed into 4-Hydroxypyridines in a subsequent cyclocondensation. The process shows broad substrate scope and leads to differentially substituted enantiopure pyridines in good to moderate yields. The preparation of diverse substituted lactic acid derived pyrid-4-yl nonaflates is described. Additional evidence for the postulated mechanism of the multicomponent reaction is presented.
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Three-Component Synthesis of Perfluoroalkyl- or Perfluoroaryl-Substituted 4-Hydroxypyridine Derivatives and Their Palladium-Catalyzed Coupling Reactions
The Journal of organic chemistry, 2010Co-Authors: Tilman Lechel, Paul Hommes, Jyotirmayee Dash, Dieter Lentz, Hans-ulrich ReissigAbstract:A three-component reaction with lithiated alkoxyallenes, nitriles, and perfluorinated carboxylic acids as precursors led to a series of perfluoroalkyl- or perfluoroaryl-substituted 4-Hydroxypyridine derivatives. These compounds were converted into 4-pyridyl nonaflates which can be employed as versatile building blocks for the synthesis of π-conjugated compounds with use of palladium-catalyzed couplings. Suzuki reactions at C-4 and C-3 of the pyridine ring proceeded with moderate to high yields. In addition, Suzuki−Miyaura, Stille, or Buchwald−Hartwig coupling reactions have also been studied and afforded the corresponding highly substituted pyridine derivatives. Starting from an arylated propargylic ether the three-component reaction led to a pentasubstituted 4-Hydroxypyridine derivative that could also be employed in palladium-catalyzed processes at C-4 and at C-3 of the pyridine core. With this simple approach the sterically highly crowded 3,4,5-triphenyl-substituted pyridine derivative 37a could be pre...
Ludwik Syper - One of the best experts on this subject based on the ideXlab platform.
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Catalytic Method for N-Methyl-4-pyridone Synthesis in the Presence of ZnAl_2O_4
Catalysis Letters, 2008Co-Authors: Hanna Grabowska, Mirosław Zawadzki, Ludwik SyperAbstract:A composite oxide ZnAl_2O_4 was prepared by microwave-assisted hydrothermal treatment, a precursor mixture of hydroxides obtained by precipitation of aluminium and zinc nitrates. Characterization by TEM, XRD and textural studies shows that ZnAl_2O_4 is nanosized and is a micro/mesoporous material with large a surface area (140 m^2/g). The gas phase catalytic methylation of 4-Hydroxypyridine in the presence of the ZnAl_2O_4 catalyst was performed in a continuous process at atmospheric pressure in the temperature range of 240–360 °C. A mixture of O - and N -alkylated products, namely 4-methoxypyridine and N -methyl-4-pyridone were obtained. The alkylation of 4-Hydroxypyridine with methanol at 345 °C offered 87.6% selectivity towards N -methyl-4-pyridone with about 89% 4-Hydroxypyridine conversion.
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Catalytic Method for N-Methyl-4-pyridone Synthesis in the Presence of ZnAl2O4
Catalysis Letters, 2007Co-Authors: Hanna Grabowska, Mirosław Zawadzki, Ludwik SyperAbstract:A composite oxide ZnAl2O4 was prepared by microwave-assisted hydrothermal treatment, a precursor mixture of hydroxides obtained by precipitation of aluminium and zinc nitrates. Characterization by TEM, XRD and textural studies shows that ZnAl2O4 is nanosized and is a micro/mesoporous material with large a surface area (140 m2/g). The gas phase catalytic methylation of 4-Hydroxypyridine in the presence of the ZnAl2O4 catalyst was performed in a continuous process at atmospheric pressure in the temperature range of 240–360 °C. A mixture of O- and N-alkylated products, namely 4-methoxypyridine and N-methyl-4-pyridone were obtained. The alkylation of 4-Hydroxypyridine with methanol at 345 °C offered 87.6% selectivity towards N-methyl-4-pyridone with about 89% 4-Hydroxypyridine conversion.
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gas phase alkylation of 2 hydroxypyridine with methanol over hydrothermally synthesised zinc aluminate
Applied Catalysis A-general, 2006Co-Authors: Hanna Grabowska, Miroslaw Zawadzki, Ludwik SyperAbstract:Abstract The gas phase alkylation of 2-hydroxypyridine with methanol at atmospheric pressure, over ZnAl 2 O 4 , prepared via hydrothermal route, is reported. The catalyst was characterised by XRD, HRTEM, DTA-TG, BET surface area measurements, pore-size analysis and surface acidity. The catalyst indicates high selectivity (over 95%) in the reaction of methanol with 2-hydroxypyridine leading to N -methyl-2-pyridone and its activity does not change substantially in the temperature range of 325–340 °C.
Hanna Grabowska - One of the best experts on this subject based on the ideXlab platform.
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Catalytic Method for N-Methyl-4-pyridone Synthesis in the Presence of ZnAl_2O_4
Catalysis Letters, 2008Co-Authors: Hanna Grabowska, Mirosław Zawadzki, Ludwik SyperAbstract:A composite oxide ZnAl_2O_4 was prepared by microwave-assisted hydrothermal treatment, a precursor mixture of hydroxides obtained by precipitation of aluminium and zinc nitrates. Characterization by TEM, XRD and textural studies shows that ZnAl_2O_4 is nanosized and is a micro/mesoporous material with large a surface area (140 m^2/g). The gas phase catalytic methylation of 4-Hydroxypyridine in the presence of the ZnAl_2O_4 catalyst was performed in a continuous process at atmospheric pressure in the temperature range of 240–360 °C. A mixture of O - and N -alkylated products, namely 4-methoxypyridine and N -methyl-4-pyridone were obtained. The alkylation of 4-Hydroxypyridine with methanol at 345 °C offered 87.6% selectivity towards N -methyl-4-pyridone with about 89% 4-Hydroxypyridine conversion.
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Catalytic Method for N-Methyl-4-pyridone Synthesis in the Presence of ZnAl2O4
Catalysis Letters, 2007Co-Authors: Hanna Grabowska, Mirosław Zawadzki, Ludwik SyperAbstract:A composite oxide ZnAl2O4 was prepared by microwave-assisted hydrothermal treatment, a precursor mixture of hydroxides obtained by precipitation of aluminium and zinc nitrates. Characterization by TEM, XRD and textural studies shows that ZnAl2O4 is nanosized and is a micro/mesoporous material with large a surface area (140 m2/g). The gas phase catalytic methylation of 4-Hydroxypyridine in the presence of the ZnAl2O4 catalyst was performed in a continuous process at atmospheric pressure in the temperature range of 240–360 °C. A mixture of O- and N-alkylated products, namely 4-methoxypyridine and N-methyl-4-pyridone were obtained. The alkylation of 4-Hydroxypyridine with methanol at 345 °C offered 87.6% selectivity towards N-methyl-4-pyridone with about 89% 4-Hydroxypyridine conversion.
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gas phase alkylation of 2 hydroxypyridine with methanol over hydrothermally synthesised zinc aluminate
Applied Catalysis A-general, 2006Co-Authors: Hanna Grabowska, Miroslaw Zawadzki, Ludwik SyperAbstract:Abstract The gas phase alkylation of 2-hydroxypyridine with methanol at atmospheric pressure, over ZnAl 2 O 4 , prepared via hydrothermal route, is reported. The catalyst was characterised by XRD, HRTEM, DTA-TG, BET surface area measurements, pore-size analysis and surface acidity. The catalyst indicates high selectivity (over 95%) in the reaction of methanol with 2-hydroxypyridine leading to N -methyl-2-pyridone and its activity does not change substantially in the temperature range of 325–340 °C.
