498-07-7Relevant articles and documents
A one-pot reaction for biorefinery: Combination of solid acid and base catalysts for direct production of 5-hydroxymethylfurfural from saccharides
Takagaki, Atsushi,Ohara, Mika,Nishimura, Shun,Ebitani, Kohki
, p. 6276 - 6278 (2009)
5-Hydroxymethylfurfural (HMF), one of the most important intermediates derived from biomass, was directly produced from monosaccharides (fructose and glucose) and disaccharides (sucrose and cellobiose) by a simple one-pot reaction including hydrolysis, isomerization and dehydration using solid acid and base catalysts under mild conditions.
Uncatalysed wet oxidation of d-glucose with hydrogen peroxide and its combination with hydrothermal electrolysis
Moreno, Teresa,Kouzaki, Goushi,Sasaki, Mitsuru,Goto, Motonobu,Cocero, María José
, p. 33 - 38 (2012)
An increasing interest in biomass as a renewable feedstock for the chemical industry has risen over the last decades, and glucose, the monomer unit of cellulose, has been widely studied as a source material to produce value-added products such as carboxylic acids, mainly gluconic and formic. In this work, the non-catalysed wet oxidation of glucose using hydrogen peroxide has been analysed, obtaining molar yields to gluconic and formic acids up to 15% and 64%, respectively. Glucose conversion was generally between 40 and 50%, reaching over 80% under the highest temperature (200°C). An appropriate choice of temperature can tune product distribution as well as reaction rates. The interaction of the wet oxidation with an electrolytic reaction was also analysed.
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Montgomery et al.
, p. 3,6 (1943)
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Free energy landscape for glucose condensation and dehydration reactions in dimethyl sulfoxide and the effects of solvent
Qian, Xianghong,Liu, Dajiang
, p. 50 - 60 (2014)
The mechanisms and free energy surfaces (FES) for the initial critical steps during proton-catalyzed glucose condensation and dehydration reactions were elucidated in dimethyl sulfoxide (DMSO) using Car-Parrinello molecular dynamics (CPMD) coupled with me
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Karrer,Smirnoff
, p. 817,820 (1921)
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Syntheses of 5-hydroxymethylfurfural and levoglucosan by selective dehydration of glucose using solid acid and base catalysts
Ohara, Mika,Takagaki, Atsushi,Nishimura, Shun,Ebitani, Kohki
, p. 149 - 155 (2010)
Selective dehydration of glucose, the most abundant monosaccharide, was examined using a solid acid catalyst individually or a combination of solid acid and base catalysts to form anhydroglucose (levoglucosan) or 5-hydroxymethylfurfural (HMF), respectively. Glucose was dehydrated to anhydroglucose by acid catalysis in polar aprotic solvents including N,N-dimethylformamide. Amberlyst-15, a strongly acidic ion-exchange resin, functioned as an efficient solid acid catalyst for anhydroglucose production with high selectivity. In the presence of solid base, aldose-ketose isomerization of glucose to fructose preferentially occurred by base catalysis, even in coexistence with the solid acid, resulting in successive dehydration of fructose to 5-hydroxymethylfurfural by acid catalysis with high yield in a one-pot reaction. A combination of Amberlyst-15 and hydrotalcite, an anionic layered clay, afforded high HMF selectivity under a moderate reaction temperature, owing to prevention of anhydroglucose formation.
Biochemical Characterization and Mechanistic Analysis of the Levoglucosan Kinase from Lipomyces starkeyi
Rother, Christina,Gutmann, Alexander,Gudiminchi, Ramakrishna,Weber, Hansj?rg,Lepak, Alexander,Nidetzky, Bernd
, p. 596 - 603 (2018)
Levoglucosan kinase (LGK) catalyzes the simultaneous hydrolysis and phosphorylation of levoglucosan (1,6-anhydro-β-d-glucopyranose) in the presence of Mg2+–ATP. For the Lipomyces starkeyi LGK, we show here with real-time in situ NMR spectroscopy at 10 °C and pH 7.0 that the enzymatic reaction proceeds with inversion of anomeric stereochemistry, resulting in the formation of α-d-glucose-6-phosphate in a manner reminiscent of an inverting β-glycoside hydrolase. Kinetic characterization revealed the Mg2+ concentration for optimum activity (20–50 mm), the apparent binding of levoglucosan (Km=180 mm) and ATP (Km=1.0 mm), as well as the inhibition by ADP (Ki=0.45 mm) and d-glucose-6-phosphate (IC50=56 mm). The enzyme was highly specific for levoglucosan and exhibited weak ATPase activity in the absence of substrate. The equilibrium conversion of levoglucosan and ATP lay far on the product side, and no enzymatic back reaction from d-glucose-6-phosphate and ADP was observed under a broad range of conditions. 6-Phospho-α-d-glucopyranosyl fluoride and 6-phospho-1,5-anhydro-2-deoxy-d-arabino-hex-1-enitol (6-phospho-d-glucal) were synthesized as probes for the enzymatic mechanism but proved inactive with the enzyme in the presence of ADP. The pyranose ring flip 4C1→1C4 required for 1,6-anhydro-product synthesis from d-glucose-6-phosphate probably presents a major thermodynamic restriction to the back reaction of the enzyme.
Applications of Shoda's reagent (DMC) and analogues for activation of the anomeric centre of unprotected carbohydrates
Fairbanks, Antony J.
, (2020/12/07)
2-Chloro-1,3-dimethylimidazolinium chloride (DMC, herein also referred to as Shoda's reagent) and its derivatives are useful for numerous synthetic transformations in which the anomeric centre of unprotected reducing sugars is selectively activated in aqueous solution. As such unprotected sugars can undergo anomeric substitution with a range of added nucleophiles, providing highly efficient routes to a range of glycosides and glycoconjugates without the need for traditional protecting group manipulations. This mini-review summarizes the development of DMC and some of its derivatives/analogues, and highlights recent applications for protecting group-free synthesis.
Carbon Materials as Phase-Transfer Promoters for Obtaining 5-Hydroxymethylfurfural from Cellulose in a Biphasic System
Faba, Laura,Garcés, Diego,Díaz, Eva,Ordó?ez, Salvador
, p. 3769 - 3777 (2019/07/04)
Different carbonaceous materials were tested as mass-transfer promoters for increasing the yield of 5-hydroxymethylfurfural (5-HMF) in biphasic cellulose hydrolysis. The benefits of working with a biphasic system (water/methyl isobutyl ketone) under soft acid conditions were taken as starting point (no humins or levulinic acid production), with slow extraction kinetics as the weakest point of this approach. Carbon nanotubes (CNTs) and activated carbon (AC) were proposed to improve 5-HMF liquid–liquid mass transfer. A kinetic analysis of the extraction process indicated the competition between 5-HMF and glucose adsorption as the main cause of the poor results obtained with AC. In contrast, very promising results were obtained with CNTs, mainly at 1.5 wt % loading, with complete transfer of HMF and a high global mass-transfer coefficient. The use of CNTs improved the amount of 5-HMF in the organic phase by more than 270 %.
