3128-06-1Relevant articles and documents
Levulinic acid production from Cicer arietinum, cotton, Pinus radiata and sugarcane bagasse
Victor, Amudhavalli,Pulidindi, Indra Neel,Gedanken, Aharon
, p. 44706 - 44711 (2014)
Levulinic acid is a key platform chemical. Even gasoline range chemicals could be produced from levulinic acid making it a strategically significant compound. Producing levulinic acid from biomass is attractive from economic as well as environmental aspec
Selective glucose transformation by titania as a heterogeneous Lewis acid catalyst
Nakajima, Kiyotaka,Noma, Ryouhei,Kitano, Masaaki,Hara, Michikazu
, p. 100 - 105 (2014)
The Lewis acidity of phosphate-immobilized anatase TiO2 (phosphate/TiO2) has been studied to develop novel environmentally benign reaction systems. Fourier transform infrared (FT-IR) measurements suggested that most Lewis acid sites on bare and phosphate/TiO2 surface function even in water. phosphate/TiO2 exhibits high catalytic performance for selective 5-(hydroxymethyl)furfural (HMF) production from glucose in THF/water (90/10 vol.%) solution. This is attributed to water-tolerant Lewis acid sites on phosphate/TiO2 that promote step-wise conversion of glucose into HMF. The catalyst was easily recovered from reaction solution by simple decantation or filtration, and can be used repeatedly without significant loss of original activity for subsequent reactions.
Solid acid-catalyzed cellulose hydrolysis monitored by in situ Atr-Ir spectroscopy
Zakzeski, Joseph,Grisel, Ruud J. H.,Smit, Arjan T.,Weckhuysen, Bert M.
, p. 430 - 437 (2012)
The solid acid-catalyzed hydrolysis of cellulose was studied under elevated temperatures and autogenous pressures using in situ ATR-IR spectroscopy. Standards of cellulose and pure reaction products, which include glucose, fructose, hydroxymethylfurfural (HMF), levulinic acid (LA), formic acid, and other compounds, were measured in water under ambient and elevated temperatures. A combination of spectroscopic and HPLC analysis revealed that the cellulose hydrolysis proceeds first through the disruption of the glycosidic linkages of cellulose to form smaller cellulose molecules, which are readily observed by their distinctive C-O vibrational stretches. The continued disruption of the linkages in these oligomers eventually results in the formation and accumulation of monomeric glucose. The solid-acid catalyst accelerated the isomerization of glucose to fructose, which then rapidly reacted under hydrothermal conditions to form degradation products, which included HMF, LA, formic acid, and acetic acid. The formation of these species could be suppressed by decreasing the residence time of glucose in the reactor, reaction temperature, and contact with the metal reactor. The hydrolysis of regenerated cellulose proceeded faster and under milder conditions than microcrystalline cellulose, which resulted in increased glucose yield and selectivity. Vibrating acids: The solid acid-catalyzed hydrolysis of cellulose has been studied by using in situ ATR-IR spectroscopy. It is possible to monitor the formation and consumption of important products and intermediates by their distinctive vibrational characteristics under the reaction conditions. Copyright
Synergistic catalytic effect of the ZnBr2-HCl system for levulinic acid production using microwave irradiation
Kumar, Vijay Bhooshan,Pulidindi, Indra Neel,Gedanken, Aharon
, p. 11043 - 11048 (2015)
A catalytic process for the selective conversion of carbohydrates to levulinic acid is developed. A synergy in the catalytic action is observed when a combination of ZnBr2 and HCl was used as the catalyst which is attributed to the in situ generation of HBr. Carbohydrates, namely, glucose, molasses and sucrose, were employed as feedstock for levulinic acid production. Microwave irradiation of glucose either in the presence of HCl alone or both HCl and ZnBr2 as catalysts yielded the formation of levulinic acid. But the conversion of glucose to levulinic acid was much faster (only 6 min) when both HCl and ZnBr2 were employed together. The effect of the reaction parameters like, the time of irradiation, % power, and amount of substrate and catalyst on the yield of levulinic acid were studied. The reaction products in each case were analysed using 1H and 13C NMR. The yield of levulinic acid was estimated using HPLC. The maximum yield of levulinic acid obtained from glucose was 53 wt%.
A new functionalized ionic liquid for efficient glucose conversion to 5-hydroxymethyl furfural and levulinic acid
Ramli, Nur Aainaa Syahirah,Amin, Nor Aishah Saidina
, p. 113 - 121 (2015)
The conversion of glucose to 5-hydroxymethyl furfural (5-HMF) and levulinic acid (LA) using ionic liquid is a promising method for producing liquid fuels from renewable resources. In this study, three types of acidic functionalized ionic liquids (FILs) were prepared and used as catalysts in the conversion of glucose to 5-HMF and LA. The prepared FILs were characterized using CHNS elemental analysis and 1H and 13C NMR. The acidity of the FILs was examined using pyridine-FTIR, Hammett and acid-base titration methods. The FIL with high acidity and with both Br?nsted and Lewis acid sites present seemed suitable for 5-HMF and LA production. Among the tested FILs, 1-sulfonic acid-3-methyl imidazolium tetrachloroferrate ([SMIM][FeCl4]) demonstrated the highest catalytic performance. The yields of 5-HMF and LA reached as high as 18% and 68%, respectively after 4 h at 150°C. The catalyst was reused five times without significant loss of activity. Furthermore, for the kinetic analysis performed for glucose conversion, the activation energy and pre-exponential factor for the reaction were 38 kJ mol-1 and 925 min-1, respectively. The experimental results demonstrated the potential of FIL as a catalyst for biomass transformation to platform chemicals under mild process condition.
Effect of NaCl on the conversion of cellulose to glucose and levulinic acid via solid supported acid catalysis
Potvin, Joshua,Sorlien, Erin,Hegner, Jessica,DeBoef, Brenton,Lucht, Brett L.
, p. 5891 - 5893 (2011)
Cellulose is hydrolyzed to glucose, which is further converted to levulinic acid in the presence of Nafion, as a surface supported acid catalyst. The addition of simple alkali metal halide salts, including NaCl, provides significant enhancement to the yield. The catalyst can be recycled suggesting possible extension into a continuous flow reactor for the synthesis of the biofuel precursors.
Comparison of homogeneous and heterogeneous catalysts for glucose-to-fructose isomerization in aqueous media
Choudhary, Vinit,Pinar, Ana B.,Lobo, Raul F.,Vlachos, Dionisios G.,Sandler, Stanley I.
, p. 2369 - 2376 (2013)
Herein, the first comparison of the mechanisms of glucose-to-fructose isomerization in aqueous media enabled by homogeneous (CrCl3 and AlCl3) and heterogeneous catalysts (Sn-beta) by using isotopic-labeling studies is reported. A pronounced kinetic isotope effect (KIE) was observed if the deuterium label was at the C2 position, thus suggesting that a hydrogen shift from the C2 to C1 positions was the rate-limiting step with the three catalysts. 13C and 1HNMR spectroscopic investigations confirmed that an intra-hydride-transfer reaction pathway was the predominant reaction channel for all three catalysts in aqueous media. Furthermore, the deuterium atom in the labeled glucose could be mapped onto hydroxymethylfurfural and formic acid through reactions that followed the isomerization step in the presence of Br?nsted acids. In all three catalysts, the active site appeared to be a bifunctional Lewis-acidic/ Br?nsted-basic site, based on a speciation model and first-principles calculations. For the first time, a mechanistic similarities between the homogeneous and heterogeneous catalysis of aldose-to-ketose isomerization is established and it is suggested that learning from homogeneous catalysis could assist in the development of improved heterogeneous catalysts. Different strokes: Isotopic-labeling experiments reveal mechanistic similarities between homogeneous and heterogeneous catalysts for the aldose-to-ketose isomerization reaction in aqueous media. An intra-hydride transfer is the dominant reaction channel for the isomerization and a Lewis acid-Br?nsted base bifunctional site is the most active site for all three catalysts. Copyright
Conversion of hemicellulose sugars catalyzed by formic acid: Kinetics of the dehydration of D -xylose, L -arabinose, and D -glucose
Dussan, Karla,Girisuta, Buana,Lopes, Marystela,Leahy, James J.,Hayes, Michael H. B.
, p. 1411 - 1428 (2015)
The pre-treatment of lignocellulosic biomass produces a liquid stream of hemicellulose-based sugars, which can be further converted to high-value chemicals. Formosolv pulping and the Milox process use formic acid as the fractionating agent, which can be used as the catalyst for the valorisation of hemicellulose sugars to platform chemicals. The objective of this study was to investigate the reaction kinetics of major components in the hemicelluloses fraction of biomass, that is, D-xylose, L-arabinose and D-glucose. The kinetics experiments for each sugar were performed at temperatures between 130 and 170 °C in various formic acid concentrations (10-64wt %). The implications of these kinetic models on the selectivity of each sugar to the desired products are discussed. The models were used to predict the reaction kinetics of solutions that resemble the liquid stream obtained from the fractionation process of biomass using formic acid.
Oxidation of cyclohexanone and/or cyclohexanol catalyzed by Dawson-type polyoxometalates using hydrogen peroxide
Dermeche, Leila,Idrissou, Yasmina,Mazari, Tassadit,Moudjahed, Mohammed,Rabia, Cherifa
, (2022/03/07)
The oxidation of cyclohexanone, cyclohexanol or cyclohexanone/cyclohexanol mixture using as catalyst, Dawson-type polyoxometalates (POMs) of formula, α- and β-K6P2W18O62, α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62 and hydrogen peroxide, carried out at 90 °C with a reaction time of 20 h, led to a high number of mono- and di-acids which were identified by GC-MS. Levulinic, 6-hydroxyhexanoic, adipic, glutaric and succinic acids, major products were evaluated by HPLC. Regardless of the substrate nature, all POMs exhibited high catalytic activity with 94–99% of conversion, whereas the formation of the different products is sensitively related to both the composition and symmetry of the POMs and the substrate nature. The main products are adipic acid in the presence of α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62, levulinic acid in the presence of α1-K7P2Mo5VW12O62 and β-K6P2W18O62 and 6-hydroxyhexanoic acid in the presence of α- and β-K6P2W18O62. Graphical abstract: High catalytic activity was observed with?α- and?β-K6P2W18O62, α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62 Dawson-type for the oxidation of cyclohexanone, cyclohexanol or cyclohexanone/cyclohexanol mixture, in the hydrogen peroxide presence, to several oxygenated products. Adipic, levulinic and 6-hydroxyhexanoic acids are the main products. The peroxo- species formed in situ could be the active sites.[Figure not available: see fulltext.]
Selective C-C Bond Cleavage of Cycloalkanones by NaNO2/HCl
He, Tianyu,Chen, Dengfeng,Qian, Shencheng,Zheng, Yu,Huang, Shenlin
supporting information, p. 6525 - 6529 (2021/09/02)
A novel selective fragmentation of cycloalkanones by NaNO2/HCl has been established. The C-C bond cleavage reaction proceeds smoothly under mild conditions, selectively affording versatile keto acids or oxime acids. The methodology can streamline the synthesis of valuable chiral molecules and isocoumarins from readily available feedstocks.
New syntheses of haloketo acid methyl esters and their transformation to halolactones by reductive cyclization
China, H.,Dohi, T.,Fujitake, M.,Kageyama, N.,Kikushima, K.,Yatabe, H.
, p. 1804 - 1810 (2020/10/16)
A new method for haloketo acid methyl ester synthesis on the basis of the ring-opening of cyclic α,β-unsaturated ketones followed by halogenation under mild conditions is reported. Di- and tri-haloketo acid methyl esters are conveniently synthesized via the hydrolytic ring-opening reaction through this method. Halolactones were readily obtained from these haloketo acid methyl esters by reductive cyclization employing NaBH4 and trifluoroacetic acid. Derivatizations of the obtained halolactone utilizing the exo-halomethylene moiety were also demonstrated.
