Hydrogenation
Mostrando 1-12 de 214 artigos, teses e dissertações.
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1. Heteroannulation Reaction of α-Aminoketones for the Efficient Synthesis of 4-Imidazolin-2-ones and 2-Thiones
The hydrogenation of α-oximinoketones in methanol/HCl afforded α-aminoketones, which were applied without purification to the synthesis of 4-imidazolin-2-ones and 2-thiones, including chiral derivatives. The latter two series were obtained in high yields by a heteroannulation reaction of α-aminoketones with isocyanates and isothiocyanates, respectively. A
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Theoretical Calculations on the Mechanism of Hydrogenation of Diphenylacetylene over Pdn (n = 1-4) Clusters
Diphenylacetylene (DPA) is a precursor of stilbene and benzil, and reduction of DPA or its derivatives with metallic reagents is both an old and contemporary topic of research. By means of density function theory (DFT) calculations, a detailed investigation of the mechanism of the hydrogenation of DPA over Pd clusters was carried out at the molecular level.
J. Braz. Chem. Soc.. Publicado em: 2020-10
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3. COVID-19: Um Novo Desafio para a Cardiopatia na Gravidez
This work presents the results obtained for the gas chromatography-mass spectrometry (GC-MS) monitoring of the liquid-phase hydrodeoxygenation (HDO) reaction of furfural (FFR) to 2-methylfuran (MF) over a bifunctional Ru/RuOx/C catalyst in the presence of a direct source of H2. Hydrogenation and hydrogenolysis reactions of FFR and of the intermediate furfury
Arq. Bras. Cardiol.. Publicado em: 2020-07
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4. Furfural Hydrodeoxygenation over a Ruthenium-Based Bifunctional Catalyst in the Presence of a Direct Source of H2
This work presents the results obtained for the gas chromatography-mass spectrometry (GC-MS) monitoring of the liquid-phase hydrodeoxygenation (HDO) reaction of furfural (FFR) to 2-methylfuran (MF) over a bifunctional Ru/RuOx/C catalyst in the presence of a direct source of H2. Hydrogenation and hydrogenolysis reactions of FFR and of the intermediate furfury
J. Braz. Chem. Soc.. Publicado em: 2020-07
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5. Influence of the Capping Agent PVP of the Outer Layer of Pd Nanocubes Surface on the Catalytic Hydrogenation of Unsaturated C−C Bonds
The excess of capping agents used during the synthesis of nanoparticles is usually removed by solvent washing. The influence of the amount of polyvinylpyrrolidone (PVP) capping agent in the catalytic activity of palladium nanocubes was evaluated, after different numbers of washing cycles in the purification step performed after the syntheses of the nanoparti
J. Braz. Chem. Soc.. Publicado em: 2020-05
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6. A RENEWABLE CATALYST FOR A RENEWABLE CHEMICAL: GRAM-SCALE CONVERSION OF FURFURAL TO FURFURYL ALCOHOL BY THE CARROT (Daucus carota)
The bioconversion of furfural to furfuryl alcohol using only carrot bits in water at room temperature and ambient pressure is presented. This reaction led to the bioreduction of furfural with 99% conversion and 99% selectivity to an alcohol. This simple and “fully” green process may represent an alternative to classic hydrogenation processes. Also, witho
Quím. Nova. Publicado em: 2020-01
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7. Gold Catalysis for Selective Hydrogenation of Aldehydes and Valorization of Bio-Based Chemical Building Blocks
Gold catalysts are best known for their selectivity in oxidation reactions, however, there is a promising future for gold in selective hydrogenations. Herein, the hydrogenation of several aldehydes and important bio-based chemical building blocks, namely 5-hydroxymethylfurfural (5-HMF), furfural and vanillin, was performed throughout the combination of Au na
J. Braz. Chem. Soc.. Publicado em: 21/10/2019
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8. New Strategies in Enantioselective Hydrogenation on Supported Transition Metal Catalyst: Effects of Metal Sintering and Support Swelling
The effect of noble metal catalysts supported on an ionic exchange resin for the enantioselective hydrogenation of ethyl pyruvate to ethyl lactate was studied. High activity and moderate enantioselectivity levels were obtained. Pt was the best enantioselective metallic phase, followed by Pd and Au; Rh was the less enantioselective metallic phase. The effect
J. Braz. Chem. Soc.. Publicado em: 12/08/2019
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9. Edaphic macrofauna in degradation of animal and vegetable residues
Resumo Este estudo objetivou avaliar a capacidade de degradar a matéria orgânica pela macrofauna edáfica (minhocas), a relação carbono/nitrogênio (C/N) e o potencial hidrogeniônico (pH), durante o processo da vermicompostagem em diferentes resíduos orgânicos. Os tratamentos foram constituídos por resíduos orgânicos de origem animal (esterco bovi
Braz. J. Biol.. Publicado em: 18/04/2019
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10. Lignin-First Biorefining of Lignocellulose: the Impact of Process Severity on the Uniformity of Lignin Oil Composition
In lignin-first biorefining via reductive processes, lignocellulosic materials are deconstructed by the solvent extraction of lignin in the presence of a hydrogenation catalyst. This approach provides a route to the successful extraction and reductive passivation of lignin fragments to produce low molar mass lignin oils together with high-quality pulps. Here
J. Braz. Chem. Soc.. Publicado em: 2019-03
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11. Wastewater treatment using adsorption process in column for agricultural purposes
Resumo A água é um recurso essencial para vida, de extrema relevância para o ecossistema e encontra-se com várias problemáticas, entre elas a escassez. Por conta disso, o presente estudo foi desenvolvido a fim de propiciar a reutilização da água residuária da Estação de Tratamento de Água de Gramame para fins agrícolas. Assim, foi realizada a in
Rev. Ambient. Água. Publicado em: 04/02/2019
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12. Stress effects on the kinetics of hydride formation and growth in metals
Abstract Although metal hydrides are considered promising candidates for solid-state hydrogen storage, their use for practical applications remains a challenge due to the limitation imposed by the slow kinetics of hydrogen uptake and release, which has driven the interest in using metal nanoparticles as advanced materials of new hydrogen-storage systems sinc
Lat. Am. j. solids struct.. Publicado em: 22/10/2018