- Unravelling the one-pot conversion of biomass-derived furfural and levulinic acid to 1,4-pentanediol catalysed by supported RANEY Ni-Sn alloy catalysts
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Bimetallic Ni-Sn alloys have been recognised as promising catalysts for the transformation of furanic compounds and their derivatives into valuable chemicals. Herein, we report the utilisation of a supported bimetallic RANEY nickel-tin alloy supported on aluminium hydroxide (RNi-Sn(x)/AlOH; x is Ni/Sn molar ratio) catalysts for the one-pot conversion of biomass-derived furfural and levulinic acid to 1,4-pentanediol (1,4-PeD). The as prepared RNi-Sn(1.4)/AlOH catalyst exhibited the highest yield of 1,4-PeD (78%). The reduction of RNi-Sn(x)/AlOH with H2 at 673-873 K for 1.5 h resulted in the formation of Ni-Sn alloy phases (e.g., Ni3Sn and Ni3Sn2) and caused the transformation of aluminium hydroxide (AlOH) to amorphous alumina (AA). The RNi-Sn(1.4)/AA 673 K/H2 catalyst contained a Ni3Sn2 alloy as the major phase, which exhibited the best yield of 1,4-PeD from furfural (87%) at 433 K, H2 3.0 MPa for 12 h and from levulinic acid (up to 90%) at 503 K, H2 4.0 MPa, for 12 h. Supported RANEY Ni-Sn(1.5)/AC and three types of supported Ni-Sn(1.5) alloy (e.g., Ni-Sn(1.5)/AC, Ni-Sn(1.5)/c-AlOH, and Ni-Sn(1.5)/γ-Al2O3) catalysts afforded high yields of 1,4-PeD (65-87%) both from furfural and levulinic acid under the optimised reaction conditions.
- Ansyah, Fathur Razi,Astuti, Maria Dewi,Hara, Takayoshi,Husain, Sadang,Mustikasari, Kamilia,Rodiansono,Shimazu, Shogo
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p. 241 - 250
(2022/01/19)
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- Reductive Electrochemical Activation of Molecular Oxygen Catalyzed by an Iron-Tungstate Oxide Capsule: Reactivity Studies Consistent with Compound i Type Oxidants
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The reductive activation of molecular oxygen catalyzed by iron-based enzymes toward its use as an oxygen donor is paradigmatic for oxygen transfer reactions in nature. Mechanistic studies on these enzymes and related biomimetic coordination compounds designed to form reactive intermediates, almost invariably using various "shunt" pathways, have shown that high-valent Fe(V)=O and the formally isoelectronic Fe(IV) =O porphyrin cation radical intermediates are often thought to be the active species in alkane and arene hydroxylation and alkene epoxidation reactions. Although this four decade long research effort has yielded a massive amount of spectroscopic data, reactivity studies, and a detailed, but still incomplete, mechanistic understanding, the actual reductive activation of molecular oxygen coupled with efficient catalytic transformations has rarely been experimentally studied. Recently, we found that a completely inorganic iron-tungsten oxide capsule with a keplerate structure, noted as {Fe30W72}, is an effective electrocatalyst for the cathodic activation of molecular oxygen in water leading to the oxidation of light alkanes and alkenes. The present report deals with extensive reactivity studies of these {Fe30W72} electrocatalytic reactions showing (1) arene hydroxylation including kinetic isotope effects and migration of the ipso substituent to the adjacent carbon atom ("NIH shift"); (2) a high kinetic isotope effect for alkyl C - H bond activation; (3) dealkylation of alkylamines and alkylsulfides; (4) desaturation reactions; (5) retention of stereochemistry in cis-alkene epoxidation; and (6) unusual regioselectivity in the oxidation of cyclic and acyclic ketones, alcohols, and carboxylic acids where reactivity is not correlated to the bond disassociation energy; the regioselectivity obtained is attributable to polar effects and/or entropic contributions. Collectively these results also support the conclusion that the active intermediate species formed in the catalytic cycle is consistent with a compound I type oxidant. The activity of {Fe30W72} in cathodic aerobic oxidation reactions shows it to be an inorganic functional analogue of iron-based monooxygenases.
- Bugnola, Marco,Shen, Kaiji,Haviv, Eynat,Neumann, Ronny
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p. 4227 - 4237
(2020/05/05)
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- One-pot selective conversion of C5-furan into 1,4-pentanediol over bulk Ni-Sn alloy catalysts in an ethanol/H2O solvent mixture
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Inexpensive bulk Ni-Sn alloy-based catalysts demonstrated a unique catalytic property in the selective conversion of C5-furan compounds (e.g., furfuraldehyde (FFald), furfuryl alcohol (FFalc), and 2-methylfuran (2-MTF)) in an ethanol/H2O solvent mixture and selectively produced 1,4-pentanediol (1,4-PeD) in a one-pot reaction. The synergistic actions between the bulk Ni-Sn alloy catalyst, hydrogen gas, and the hydroxylated H2O or ethanol/H2O solvents are believed to play a prominent role in the catalytic reactions. Bulk Ni-Sn alloy catalysts that consisted of Ni3Sn or Ni3Sn2 alloy phases allowed an outstanding yield of 1,4-PeD up to 92% (from FFald), 67% (from FFalc), and 48% (from 2-MTF) in ethanol/H2O (1.5:2.0 volume ratio) at 433 K, 3.0 MPa H2 and 12 h. As the reaction temperature increased to 453 K, the yield of 1,4-PeD slightly decreased to 87% (from FFald), whereas it slightly increased to 71% (from FFalc). The bulk Ni-Sn alloy catalysts were reusable without any significant loss of selectivity.
- Rodiansono,Dewi Astuti, Maria,Hara, Takayoshi,Ichikuni, Nobuyuki,Shimazu, Shogo
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supporting information
p. 2307 - 2315
(2019/05/21)
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- Upgrading biomass-derived furans via acid-catalysis/hydrogenation: The remarkable difference between water and methanol as the solvent
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In methanol 5-hydroxymethylfurfural (HMF) and furfuryl alcohol (FA) can be selectively converted into methyl levulinate via acidcatalysis, whereas in water polymerization dominates. The hydrogenation of HMF, furan and furfural with the exception of FA is
- Hu, Xun,Westerhof, Roel J. M.,Wu, Liping,Dong, Dehua,Li, Chun-Zhu
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p. 219 - 224
(2018/04/16)
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- Na4H3[SiW9Al3(H2O)3O37]·12H2O/H2O: a new system for selective oxidation of alcohols with H2O2 as oxidant
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This work describes a catalytic system consisting of both Na4H3[SiW9Al3(H2O)3O37]·12H2O(SiW9Al3) and water as solvents (a?small quantity of organic solvents were used as co-solvent for a few substrates) that can be good for selective oxidation of alcohols to ketones (aldehydes) using 30% H2O2 without any phase-transfer catalyst under mild reaction conditions. The catalyst system allows easy product/catalyst separation. Under the given conditions, the secondary hydroxyl group was highly chemoselectively oxidized to the corresponding ketones in good yields in the presence of primary hydroxyl group within the same molecule, and hydroxides are selectively oxidized even in the presence of alkene. Benzylic alcohols were selectively oxidized to the corresponding benzaldehydes in good yields without over oxidation products in solvent-free conditions. Nitrogen, oxygen, sulfur-based moieties, at least for the cases where these atoms are not susceptible to oxidation, do not interfere with the catalytic alcohol oxidation.
- Wang, Jianmin,Yan, Liang,Qian, Guang,Li, Shunqing,Yang, Keli,Liu, Haitao,Wang, Xiaolai
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p. 1826 - 1832
(2007/10/03)
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- Catalytic ring opening of acetylcyclopropane by water and alcohols under the action of copper or palladium salts
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The possibility of the cleavage of the C-C bond in acetylcyclopropane (ACP) under the action of water or alcohols in the presence of copper or palladium salts was demonstrated for the first time. At 175-180 °C, the reactions proceeded regioselectively wit
- Dzhemilev,Khusnutdinov,Atnabaeva,Muslimov,Parfenova,Tomilov
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p. 1242 - 1247
(2007/10/03)
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- Regioselectivity in the Semiconductor-Mediated Photooxidation of 1,4-Pentanediol
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Optimum conditions have been established for the selective semiconductor-photocatalyzed oxidation by long-wavelength ultraviolet light of the primary alcohol functionality in 1,4-pentanediol.On platinized (2percent) TiO2 powder suspended in oxygenated aqueous (4 vol percent) acetonitrile, the initial rate ratio for oxidation of the primary/secondary alcohol site was > 7.Analysis of further oxidation products allowed for mechanistic delineation of the course of the semiconductor-mediated reaction.The selectivity is attributed to the essential role of adsorption, with the criticalphotoinduced electron transfer occurring at the surface of the irradiated particle.ZrO2 and SnO2 samples were much less active than TiO2 as photocatalysts.The effects of oxygen pressure, metal cocatalyst loading, and water content of acetonitrile are discussed.
- Fox, Marye Anne,Ogawa, Haruo,Pichat, Pierre
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p. 3847 - 3852
(2007/10/02)
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