64502-89-2Relevant academic research and scientific papers
Reductive Electrochemical Activation of Molecular Oxygen Catalyzed by an Iron-Tungstate Oxide Capsule: Reactivity Studies Consistent with Compound i Type Oxidants
Bugnola, Marco,Shen, Kaiji,Haviv, Eynat,Neumann, Ronny
, p. 4227 - 4237 (2020/05/05)
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.
Selective Activation of C-OH, C-O-C, or Ca? C in Furfuryl Alcohol by Engineered Pt Sites Supported on Layered Double Oxides
An, Zhe,He, Jing,Jiang, Yitao,Ma, Xiaodan,Shu, Xin,Song, Hongyan,Xiang, Xu,Zhang, Jian,Zhang, Zhijun,Zhao, Wenfang,Zheng, Lirong,Zhu, Yanru
, p. 8032 - 8041 (2020/09/23)
The selective activation of targeted bonds in biomass-derived furfural or furfuryl alcohol with complex chemical linkages (C-C/C-H/C-O, Ca? C/Ca? O, or C-O-H/C-O-C) is of great challenge for biomass upgrading, expecting well-defined catalyst and definite catalytically active sites. This work demonstrates an efficient targeted activation to C-OH, C-O-C, or Ca? C by engineering the structure of catalytic Pt sites, affording 2-methylfuran (2-MF), tetrahydrofurfuryl alcohol (THFA), or 1,2-pentanediol (1,2-PeD) as product in the hydroconversion of furfuryl alcohol. The catalytic Pt sites have been engineered as atomic Pt, coordination unsaturated Pt-Pt in atom-thick dispersion, or coordination unsaturated 3D Pt-Pt by tailoring the Pt dispersion (single atom, 2D cluster, or 3D cluster) on Mg and Al-containing layered double oxide (Mg(Al)O) support. The selective activation of C-OH, C-O-C, or Ca? C has been traced with the FT-IR spectra recorded surface reaction. On atomic Pt, C-O-H is easily activated, with the assistance of Mg(Al)O support, with O-terminal adsorption without affecting furan C-O and Ca? C. However, Ca? C in the furan ring is easier to be activated on coordination-unsaturated Pt-Pt in atom-thick dispersion, resulting in a step-by-step hydrogenation to generate THFA. On coordination-unsaturated 3D Pt-Pt, the hydrogenolysis of furan ring is favored, resulting in the cleavage of furan C-O to produce 1,2-PeD. Also, the Mg(Al)O supports derived from Mg and Al layered double hydroxides (LDHs) here also play a key role in promoting the selectivity to 1,2-PeD by providing basic sites.
Acid catalysis dominated suppression of xylose hydrogenation with increasing yield of 1,2-pentanediol in the acid-metal dual catalyst system
Wang, Nailiang,Chen, Zhipeng,Liu, Licheng
, p. 41 - 48 (2018/05/28)
One-pot conversion of xylose to 1,2-pentanediol was investigated in a dual catalyst system composed of Ru/C and niobium phosphate as hydrogenation and acid catalysts, respectively. A series of niobium phosphate catalysts well-characterized by XRD, N2 physisorption, FT-IR, NH3-TPD, Py-IR and XPS were tested regarding the effect of their acid properties on product selectivity for the studied process. A systematic study was reported on the effect of reaction conditions. The combined yield of 21–27% to 1,2-pentanediol and its precursor 1-hydroxyl-2-pentanone was accomplished at 423 K under 3.0 Mpa hydrogen pressure in water-γ-valerolactone/cyclohexane biphasic system. At optimized conditions, the correlation between the product yield and the surface Lewis/Br?nsted ratio were analyzed. The results revealed that the lower apparent activation energy of xylose dehydration reaction catalyzed by Lewis acid site accounted for the high product selectivity for sugar intermediate and furfural hydrogenation processes, especially for the combined selectivity to 1,2-pentanediol and 1-hydroxyl-2-pentanone. This study lays the grounds for further design of improved solid acid catalysts with high selectivity of 1, 2-pentanediol.
Synthesis of aggregation pheromone components of cerambycid species through α-hydroxylation of alkylketones
Heguaburu, Viviana,do Carmo, Hugo,Parpal, Florencia,Amorós, María Eugenia,González, Andrés
supporting information, p. 1738 - 1741 (2017/04/13)
The synthesis of 3-hydroxy-2-hexanone and 2,3-hexanediol, two components of the aggregation pheromone of several cerambycid species, is disclosed in here. Starting from 2-hexanone, through an α-hydroxylation using (diacetoxyiodo)benzene, 3-hydroxy-2-hexanone is obtained in good yield. Further reduction of this compound, gives 2,3-hexanediol in excellent yield. A study of the α-hydroxylation reaction of several alkylketones using an hypervalent iodine reagent is also disclosed in here. The synthesis of optically active compounds (R)- and (S)-3-hydroxy-2-hexanone was achieved starting from 2-hexanone with nitrosobenzene and L- and D-proline respectively, in several reaction media.
A one-pot synthesis of 1,6,9,13-tetraoxadispiro(4.2.4.2)tetradecane by hydrodeoxygenation of xylose using a palladium catalyst
Jackson, Michael A.,Blackburn, Judith A.,Price, Neil P.J.,Vermillion, Karl E.,Peterson, Steven C.,Ferrence, Gregory M.
, p. 9 - 16 (2016/07/06)
In an effort to expand the number of biobased chemicals available from sugars, xylose has been converted to 1,6,9,13-tetraoxadispiro(4.2.4.2)tetradecane in a one-pot reaction using palladium supported on silica-alumina as the catalyst. The title compound is produced in 35-40% yield under 7 MPa H2 pressure at 733 K using 3-10 wt%Pd on silica-alumina catalyst. It is isolated using a combination of liquid-liquid extractions and flash chromatography. This dimer can be converted to its monomer, 2-hydroxy-(2-hydroxymethyl)tetrahydrofuran, which ring opens under acid conditions to 1,5-dihydroxy-2-pentanone. This diol can then be esterified with vinylacetate in phosphate buffer to produce 1,5-bis(acetyloxy)-2-pentanone which is an inhibitor of mammalian 11β-hydroxysteroid dehydrogenase 1. 1H and 13C nmr spectra of each of these species are reported. The single crystal X-ray structure of the title compound is also reported. These data were collected in a temperature range of 100 K-273 K and show a solid state phase change from triclinic to monoclinic between 175 K and 220 K without a conformational change.
Method For Producing 1,2-Pentanediol
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Paragraph 0257-0259, (2014/03/25)
A process for the preparation of 1,2-pentanediol by reaction of a starting material comprising one or both compounds from the group consisting of furfuryl alcohol and furfural with hydrogen in the presence of a first heterogeneous catalyst is described.
Selectivity in the Oxidation of Aliphatic Ketones by Thallic Sulphate in Aqueous Medium
Pechal, Miroslav,Strasak, Milan
, p. 374 - 380 (2007/10/02)
The effects of temperature, structure and sulphuric acid concentration on the selectivity of the oxidation of aliphatic ketones (R1COR2) (1a-g) by thallic sulphate have been investigated.With increasing temperature the quantity of internal α-hydroxyketone (3a-d) decreases and the quantity of 1-hydroxyketone (2a-d) increases in the oxidation of methyl alkyl ketone (R2>CH3) (1a-d).The same concerns to the oxidation products of hexan-3-one (1e): 2-hydroxy-hexan-3-one (2e) and 4-hydroxy-hexan-3-one (3e), respectively. "The inverse selectivity temperature" (IST) for oxidation of linear methyl alkyl ketones (1a-c) and hexan-3-one (1e) has been found.With the use of the linear free-energy relationship it has been found that the selectivity of the reaction decreases with increasing the polar and steric effects of substituents R1,R2.With increasing the sulphuric acid concentration the selctivity of the oxidation of methyl alkyl ketones (1a, 1d) increases.
