- Highly selective synthesis under benign reaction conditions of furfural dialkyl acetal using SnCl2 as a recyclable catalyst
-
A new and mild route of furfural acetalization with various alkyl alcohols catalyzed by cheap and simple SnCl2 has been developed. This process consists of the conversion of furfural to alkyl acetals under benign and mild reaction conditions (i.e., room temperature, without solvent, recyclable catalyst), achieving a very good selectivity (97-100%) and almost complete conversion of furfural. Various tin(ii) salts were used as catalysts for the upgrading of furfural to alkyl acetal in an alcoholic solution at room temperature. SnCl2 was the most active and selective catalyst toward furfural diethyl acetal. Tin(ii) chloride is a commercially available and water tolerant Lewis acid and was demonstrated to be an efficient and recyclable catalyst for the synthesis of furfural alkyl acetal. The effects of the main variables of the reaction such as the catalyst load, temperature, reaction time and alcohol nature were assessed. SnCl2 was easily recovered and reused without loss of activity and selectivity.
- Da Silva, Márcio José,Teixeira, Milena Galdino,Natalino, Ricardo
-
-
Read Online
- Ethanolysis of selected catalysis by functionalized acidic ionic liquids: An unexpected effect of ILs structural functionalization on selectivity phenomena
-
A series of functionalized hydrogen sulfate imidazolium ILs were synthesized and applied as catalysts in the reaction of glucose, xylose and fructose with ethanol. In this research, an unexpected selectivity phenomenon was observed. It showed that in this reaction functionalized ILs should be considered as a special type of catalyst. Functionalization of alkyl imidazolium ILs, especially the addition of electronegative OH groups, causes a clear and unexpected effect manifested via visible changes in the selectivity of the reaction studied. In the case of fructose, an increase in the number of OH groups affects an increase in the selectivity towards ethyl levulinate from 14.2% for [bmim]HSO4 to 20.1% for [glymim]HSO4 with an additional increase in selectivity to 5-hydroxymethyfurfural. In turn, for xylose, the introduction of OH groups to the alkyl chain was manifested by a decrease in selectivity to furfural as its ethyl acetal and an increase in selectivity to ethylxylosides. This journal is
- Nowakowska-Bogdan, Ewa,Nowicki, Janusz
-
p. 1857 - 1866
(2022/02/05)
-
- Etherification of biomass-derived furanyl alcohols with aliphatic alcohols over silica-supported nickel phosphide catalysts: Effect of surplus P species on the acidity
-
The acidity of nickel phosphide (Ni2P) catalysts plays a crucial role in producing a desired hydrodeoxygenation molecule from biomass-derived substrates; yet, it has never been explored in acid-catalyzed reactions. Herein, we demonstrated the activity of silica-supported Ni2P catalyst prepared with the nominal P/Ni ratio of 2 (Ni2P/SiO2-2P) in the etherification of furanyl alcohols (particularly, 5-(hydroxymethyl)furfural) with aliphatic alcohols including ethanol. By comparing the characteristics of Ni/SiO2, PxOy/SiO2, and Ni2P/SiO2-xP (x = 0.5 and 1), Ni2P/SiO2-2P was revealed to contain the Br?nsted and Lewis acid sites of which both contributed to the etherification reaction. Notably, the Br?nsted acidity was associated with the surplus P species added to produce the Ni2P phase. Consequently, supported Ni2P catalysts can work in acid-catalyzed reactions if an adequate ratio of Br?nsted to Lewis acid sites is provided by the amount of the surplus P species determined by adjusting the P/Ni ratio.
- Kim, Jinsung,Shin, Mi,Suh, Young-Woong
-
-
- Fructose Transformations in Ethanol using Carbon Supported Polyoxometalate Acidic Solids for 5-Ethoxymethylfurfural Production
-
A series of carbon supported polyoxometalates have been prepared and studied as acid catalysts for the fructose dehydration. The catalytic supports, microporous activated carbon (AC, SBET=1190 m2/g) and high surface area graphite (HSAG, SBET=400 m2/g), were loaded with 15 wt% of polyoxometalates: phosphotungstic acid (TPA) or tungstosilicic acid (STA). The four resulting catalysts were tested in the fructose reaction at moderate temperature 140 °C, using water and ethanol solvents. Catalytic properties have been compared with those of an acidic resin, Amberlyst 15. As relevant findings the specific interactions of carbon supports and polyoxometalates let the inhibition of active phase lixiviation. An improved catalyst (STA-HSAG) in terms of selectivity to valuable products (ethoxymethylfurfural and ethyl levulinate) and high specific catalytic activity using ethanol as solvent has been developed. This catalyst can be reused after regeneration by washing with organic solvents.
- García-Bosch, Nadia,Bachiller-Baeza, Belén,Rodríguez-Ramos, Inmaculada,Guerrero-Ruiz, Antonio
-
p. 3746 - 3753
(2018/08/07)
-
- SWEET TASTE MODULATORS
-
Sweet taste modulators for enhancing sweetness of an oral consumer product having a sweetener are described. The sweet taste modulators include 5-ethoxymethyl-2-furaldehyde, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2,3,4-trihydroxybenzoic acid, 2,4,6-trihydroxybenzoic acid and 3,4,5-trihydroxybenzoic acid, syringic aldehyde, sinapic aldehyde, ester of 5-hydroxymethylfurfural and vanillic acid, 4-hydrozybenzaldehyde, and 5-methoxymethylfurfural. A method of making 5-ethoxymethyl-2-furaldehyde and a method of making an oral consumer product are also described.
- -
-
Paragraph 0071-0075
(2018/11/02)
-
- Direct versus acetalization routes in the reaction network of catalytic HMF etherification
-
The etherification of HMF (5-hydroxymethylfurfural) to EMF (5-(ethoxymethyl)furan-2-carbaldehyde) is studied over a series of MFI-type zeolite catalysts containing different heteroatoms (B, Fe, Al), aiming to understand the effect of different isomorph substitutions in the MFI framework on the reaction pathways of HMF conversion. The rate constants in the reaction network are determined for these different catalysts and analyzed with respect to the amount of Br?nsted and Lewis acid sites determined by FT-IR pyridine adsorption. Two different pathways of EMF formation, i.e. direct etherification and via acetalization, were evidenced. The Lewis acid sites generated from the presence of aluminum are primarily active in catalyzing direct HMF etherification to EMF, which has a rate constant about one order of magnitude lower than the etherification of the corresponding acetals. This behaviour is due to the competitive chemisorption between hydroxyl and aldehyde groups (both present in HMF) on the Lewis acid sites catalyzing the etherification. A cooperation phenomenon between Br?nsted and Lewis acid sites is observed for the HMF acetal etherification to EMF acetal. In the reactions of direct HMF acetalization and deacetalization of the EMF acetal, the turnover frequencies for Silicalite-1 and B-MFI samples are about twice those for Fe-MFI and Al-MFI samples. This is attributed to the different reactivity of strong silanol groups associated with surface defects on the external surface in Silicalite-1 and B-MFI. These sites are also responsible for the EMF-to-EOP (ethyl 4-oxopentanoate) reaction step. In the deacetalization reaction of the EMF acetal, the behavior is determined from the presence of water (product of reaction) favouring the back reaction (aldehyde formation).
- Lanzafame,Papanikolaou,Perathoner,Centi,Migliori,Catizzone,Aloise,Giordano
-
p. 1304 - 1313
(2018/03/13)
-
- Cascade Reductive Etherification of Bioderived Aldehydes over Zr-Based Catalysts
-
An efficient one-pot catalytic cascade sequence has been developed for the production of value-added ethers from bioderived aldehydes. Etherification of 5-(hydroxymethyl)furfural with different aliphatic alcohols over acidic Zr–montmorillonite (Zr-Mont) catalyst produced a mixture of 5-(alkoxymethyl)furfural and 2-(dialkoxymethyl)-5-(alkoxymethyl)furan. The latter was selectively converted back into 5-(alkoxymethyl)furfural by treating it with water over the same catalyst. The synthesis of 2,5-bis(alkoxymethyl)furan was achieved through a cascade sequence involving etherification, transfer hydrogenation, and re-etherification over a combination of acidic Zr-Mont and the charge-transfer hydrogenation catalyst [ZrO(OH)2]. This catalyst combination was further explored for the cascade conversion of 2-furfuraldehyde into 2-(alkoxymethyl)furan. The scope of this strategy was then extended for the reductive etherification of lignin-derived arylaldehydes to obtain the respective benzyl ethers in >80 % yield. Additionally, the mixture of Zr-Mont and ZrO(OH)2 does not undergo mutual destruction, which was proved by recycling experiments and XRD analysis. Both the catalysts were thoroughly characterized using BET, temperature-programmed desorption of NH3 and CO2, pyridine-FTIR, XRD, inductively coupled plasma optical emission spectroscopy, and X-ray photoelectron spectroscopy techniques.
- Shinde, Suhas,Rode, Chandrashekhar
-
p. 4090 - 4101
(2017/10/18)
-
- Sulfonated graphene oxide as effective catalyst for conversion of 5-(hydroxymethyl)-2-furfural into biofuels
-
The acid-catalyzed reaction of 5-(hydroxymethyl)-2-furfural with ethanol is a promising route to produce biofuels or fuel additives within the carbohydrate platform; specifically, this reaction may give 5-ethoxymethylfurfural, 5-(ethoxymethyl)furfural diethylacetal, and/or ethyl levulinate (bioEs). It is shown that sulfonated, partially reduced graphene oxide (S-RGO) exhibits a more superior catalytic performance for the production of bioEs than several other acid catalysts, which include sulfonated carbons and the commercial acid resin Amberlyst-15, which has a much higher sulfonic acid content and stronger acidity. This was attributed to the cooperative effects of the sulfonic acid groups and other types of acid sites (e.g., carboxylic acids), and to the enhanced accessibility to the active sites as a result of the 2D structure. Moreover, the acidic functionalities bonded to the S-RGO surface were more stable under the catalytic reaction conditions than those of the other solids tested, which allowed its efficient reuse. Graphene on the scene: Sulfonated, partially reduced graphene oxide (S-RGO) exhibits a superior catalytic performance than other carbocatalysts and Amberlyst-15 in the acid-catalyzed conversion of 5-(hydroxymethyl)-2-furfural to products for biofuels. The beneficial effects are associated with the 2D structure of S-RGO and its acidic surface enriched with sulfur and oxygen functionalities.
- Antunes, Margarida M.,Russo, Patrícia A.,Wiper, Paul V.,Veiga, Jacinto M.,Pillinger, Martyn,Mafra, Luís,Evtuguin, Dmitry V.,Pinna, Nicola,Valente, Anabela A.
-
p. 804 - 812
(2014/03/21)
-
- A continuous flow strategy for the coupled transfer hydrogenation and etherification of 5-(hydroxymethyl)furfural using lewis acid zeolites
-
Hf-, Zr- and Sn-Beta zeolites effectively catalyze the coupled transfer hydrogenation and etherification of 5-(hydroxymethyl)furfural with primary and secondary alcohols into 2,5-bis(alkoxymethyl)furans, thus making it possible to generate renewable fuel
- Lewis, Jennifer D.,Van De Vyver, Stijn,Crisci, Anthony J.,Gunther, William R.,Michaelis, Vladimir K.,Griffin, Robert G.,Roman-Leshkov, Yuriy
-
p. 2255 - 2265
(2014/11/08)
-
- Efficient production of 5-hydroxymethylfurfural and alkyl levulinate from biomass carbohydrate using ionic liquid-based polyoxometalate salts
-
Direct conversion of fructose into 5-hydroxymethylfurfural (HMF) and alkyl levulinate is achieved by making use of ionic liquid-based polyoxometalate salts (IL-POMs) as solid acid catalysts. Among these solid acids, phosphotungstic acid-derived IL-POM shows the highest catalytic performance in both the HMF and ethyl levulinate (EL) formation. A study for optimizing the reaction conditions such as the reaction time and the temperature has been performed. High HMF and EL yields of up to 99% and 82%, respectively, are obtained from fructose under the investigated conditions. Moreover, the generality of the catalyst is further demonstrated by processing representative di- and polysaccharides such as sucrose and inulin with good yields to HMF (76% from inulin and 48% from sucrose) and EL (67% from inulin and 45% from sucrose), again under mild conditions, thereby eliminating the separate hydrolysis step before the dehydration reaction. The catalyst recycling experiment indicates that the adsorption and accumulation of oligomeric products on the catalyst surface results in a partial deactivation of catalyst. The mechanism research reveals that a major pathway for EL formation involves a fructose-to-HMF transformation followed by HMF etherification and rehydration of HMF-ether to give EL. The research highlights an efficient, environment-friendly and recyclable solid acid for biomass valorization.
- Chen, Jinzhu,Zhao, Guoying,Chen, Limin
-
p. 4194 - 4202
(2014/01/06)
-
- Production of biomass-derived furanic ethers and levulinate esters using heterogeneous acid catalysts
-
Mesoporous aluminosilicates of the type Al-TUD-1, prepared via "green", low-cost, non-surfactant templating routes, are effective and versatile heterogeneous acid catalysts for the production of useful bio-based furanic ethers and levulinate esters, via the reactions of the biorenewable substrates 5-hydroxymethyl-2-furfural (Hmf) or furfuryl alcohol (FA) with aliphatic alcohols. The identification of reaction intermediates and products by comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry was carried out, giving mechanistic insights. Ethyl levulinate (EL) was formed from FA or Hmf as substrates, with higher EL yields being reached in the former case. Different types of alkyl levulinates may be synthesized from FA using Al-TUD-1 catalysts. On the other hand, 5-(ethoxymethyl)furan-2-carbaldehyde may be formed as the main product from Hmf. Modifications of the properties of Al-TUD-1 involved varying the Si/Al ratio and applying a post-synthesis acid treatment. The influence of these factors and of the reaction conditions on the catalytic reactions was investigated. The efficient regeneration and recyclability of Al-TUD-1 was assessed.
- Neves, Patricia,Antunes, Margarida M.,Russo, Patricia A.,Abrantes, Joana P.,Lima, Sergio,Fernandes, Auguste,Pillinger, Martyn,Rocha, Silvia M.,Ribeiro, Maria F.,Valente, Anabela A.
-
p. 3367 - 3376
(2013/12/04)
-
- Etherification and reductive etherification of 5-(hydroxymethyl)furfural: 5-(alkoxymethyl)furfurals and 2,5-bis(alkoxymethyl)furans as potential bio-diesel candidates
-
A low energy intensive process for the production of diesel fuel has been delineated from both 5-(hydroxymethyl)furfural (HMF) and its sugar precursor d-(-)-fructose. Alcoholic solutions of the above produced a mixture of potential bio-diesel candidates namely, 5-(alkoxymethyl)furfural, 5-(alkoxymethyl) furfural dialkylacetal, and alkyl levulinate, in the presence of solid acid catalysts. Sulfonic acid functionalized resins, Amberlyst-15 and Dowex DR2030 showed exceptional reactivity and selectivity for these reactions. Production of another potential diesel candidate 2,5-bis(alkoxymethyl)furan has been optimized through both sequential reduction/etherification and one-pot reductive etherification processes. During the metal catalyzed hydrogenation of HMF, platinum showed an exclusive selectivity for the reduction of the carbonyl functionality of HMF. Both Pt and Pt/Sn supported on Al2O3 catalysts have been optimized for the production of 2,5-bis(alkoxymethyl)furan from HMF. The reaction mechanisms of etherification and reductive etherification have been discussed in detail on the basis of intermediates observed during these processes. The Royal Society of Chemistry.
- Balakrishnan, Madhesan,Sacia, Eric R.,Bell, Alexis T.
-
p. 1626 - 1634
(2013/02/22)
-