- Acetalisation of bio-glycerol with acetone to produce solketal over sulfonic mesostructured silicas
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Sulfonic acid-functionalized mesostructured silicas have demonstrated excellent catalytic behaviour in the acetalisation of glycerol with acetone to yield 2,2-dimethyl-1,3-dioxolane-4-methanol, also known as solketal. This molecule constitutes an excellent compound for the formulation of gasoline, diesel and biodiesel fuels. The activity achieved with arenesulfonic acid-functionalized silica is comparable to that displayed by Amberlyst-15. Optimal production of solketal over arenesulfonic acid mesostructured silica has been established for a reaction system consisting of three consecutive 2-step batches (30 min under reflux and an evaporation step under vacuum), and using a 6/1 acetone/glycerol molar ratio. The use of lower grades of glycerol, such as technical (purity of 91.6 wt%) and crude (85.8 wt%) glycerol, has also provided high conversions of glycerol over sulfonic acid-modified heterogeneous catalysts (84% and 81%, respectively). For refined and technical glycerol the catalysts have been reused, without any regeneration treatment, up to three times, keeping the high initial activity. However, the high sodium content in crude glycerol deactivates the sulfonic acid sites by cation exchange. This deactivation is readily reversed by simple acidification of the catalyst after reaction.
- Vicente, Gemma,Melero, Juan A.,Morales, Gabriel,Paniagua, Marta,Martin, Eric
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- Selective glycerol transformations to high value-added products catalysed by aluminosilicate-supported iron oxide nanoparticles
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Conversion of glycerol to cyclic acetals (with paraformaldehyde, benzaldehyde, furfural and acetone) and to mono-, di- and triacetylglycerides (with levulinic acid) was investigated using a supported iron oxide nanoparticle system of a mesoporous aluminosilicate heterogeneous catalyst (Fe/Al-SBA-15). The effect of various parameters on the reaction, temperature, mol% of catalyst or ratio of glycerol:substrate were studied. An optimization of the reaction conditions carried out with glycerol by means of experimental design methodology showed that a very high glycerol conversion (99%) and high combined selectivity toward di- and triacetylglycerides could be obtained under optimized conditions. All of the acetalisation reactions carried out at 100 °C also gave good to excellent conversions and selectivities to target products, illustrating the potential of Fe/Al-SBA-15 as a highly active, stable and reusable heterogeneous catalyst in glycerol acid-catalysed transformations.
- Gonzalez-Arellano, Camino,De, Sudipta,Luque, Rafael
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- Intramolecular Chirality Transfer [2 + 2] Cycloadditions of Allenoates and Alkenes
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Intramolecular chirality transfer [2 + 2] cycloaddition of enantiomerically enriched allenoates and alkenes is presented. The use of a chiral catalyst was found to be critical to achieve high levels of diastereoselectivity compared to use of an achiral catalyst. The method developed leads to highly substituted cyclobutanes that would be difficult to prepare by alternative methods.
- Xu, Yao,Hong, Young J.,Tantillo, Dean J.,Brown, M. Kevin
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- Solventless acetalization of glycerol with acetone to fuel oxygenates over Ni-Zr supported on mesoporous activated carbon catalyst
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Glycerol was selectively converted to branched oxygenated compounds (five membered ring solketal, 5, and six membered ring acetal, 6) through a solventless acetalization process with acetone catalyzed by mesoporous 5%Ni-1%Zr/AC catalyst. The reaction was carried out under nitrogen flow conditions using 0.20 g of catalyst at 45 C. The conversion of glycerol was almost complete with corresponding selectivity of 26% and 74% toward 5 and 6 components, respectively. The catalytic activity was mainly attributed to the intercalated NiO and ZrO2 species into the AC structure and to the surface characteristics as well. Zirconium species are essential co-catalysts with Ni species. The prepared catalysts were characterized for their intrinsic physicochemical and textural properties using BET surface area, XRD, XPS, TPR, FTIR, and EDX. The effect of different operational parameters such as reaction temperature, molar ratio of glycerol/acetone, catalyst weight and reaction time was investigated. The stability of the catalytic activity was examined through leaching and reusability tests.
- Khayoon,Hameed
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- Toward sustainable and eco-efficient novel catalytic distillation process for production of solketal using seepage catalytic packing internal
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The initial aim of this paper is to dramatically improve the post-treatment stage of biodiesel production, which converts problematic glycerol to solketal (SK), by introduction of an eco-efficient integrated reactive and dividing wall distillation process. To overcome the chemical equilibrium limitations and the long post-treatment process with the high energy consumption and waste water emission, this study provides the potentially, sustainable and novel reactive distillation (RD) process for cleanly catalytic synthesis of SK, taking into account costs and environmental impact. The ketalization kinetics experiments were carried out to provide a basis for subsequent experiments and simulations. A reliable model was established for further RD technological design and validated by the pilot-scale experiments. Through sensitivity analysis, the effects of multiplex parameters in RD process were determined. The advanced intensification of SK production by reactive dividing wall column (RDWC) achieves reduction in energy, total annual cost (TAC) and CO2 emissions of 13.9 %, 18.2 % and 16.4 % (as oil resources), respectively, compared to the optimal SK production by RD process. This proposed technology is also compared with the conventional industrial route of ketalization with 18.7 % energy saving.
- Cong, Haifeng,Gao, Xin,Lai, Jianing,Li, Hong,Li, Xingang,Shu, Chang,Wang, Yiwei,Zhao, Runnan
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- Selective cleavage of ethers using silica-alumina gel catalysts prepared by the sol-gel method
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The selective cleavage of tetrahydropyranyl (THP), methoxymethyl (MOM), 1-ethoxyethyl (EE), 1-methyl-1-methoxyethyl (MME) and trimethylsilyl (TMS) ether groups with silica-alumina gels prepared by the sol-gel method has been investigated. The deprotection rate follows the order: TMS > MME >>, EE > THP >> MOM. The selective deprotection of diol derivatives with mixed protecting groups was achieved efficiently. Bis-THP and bis-MOM ether derivatives of a substrate which contained a primary and a tertiary hydroxyl groups were mono- deprotected with moderate selectivity. The selective deprotection of glycerol ethers was also examined. The silica-alumina gels prepared by the sol-gel method are thus shown to be a good catalyst for selective cleavage of ether protecting groups giving the product in a simple manner under mild conditions.
- Matsumoto, Yoshihiko,Mita, Keisuke,Hashimoto, Keiji,Iio, Hideo,Tokoroyama, Takashi
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- Choice of a catalyst and technological scheme for synthesis of solketal
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Results are presented obtained in tests of various homogeneous and heterogeneous catalysts in a synthesis of solketal (2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane). It is shown that, all other conditions being the same, the highest catalytic activity is observed for sulfuric acid and beta zeolite. Data are presented on how the equilibrium constant of the reaction of glycerol ketalization depends on temperature. A technological scheme of the process for synthesis of solketal is suggested and its description is presented.
- Dmitriev,Terekhov,Zanaveskin,Khadzhiev,Zanaveskin,Maksimov
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- Investigations on heterogeneously catalysed condensations of glycerol to cyclic acetals
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The acid-catalysed condensation of glycerol, a chemical from renewable materials, with benzaldehyde, formaldehyde, acetone (acetalisation), and their dimethyl acetals (transacetalisation) to mixtures of [1,3]dioxan-5-ols and [1,3]dioxolan-4-yl-methanols was investigated. Various solid acids were evaluated as heterogeneous catalysts for the desired glycerol conversion into these potential novel platform chemicals. [1,3]dioxan-5-ols are of particular interest as precursors for 1,3-propanediol derivatives. Therefore, the reported investigations were focused on the identification of reaction conditions that promote the formation of [1,3]dioxan-5-ols and suppress the formation of [1,3]dioxolan-4-yl-methanols.
- Deutsch,Martin,Lieske
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- Synthesis of glycerol-derived 4-alkyl-substituted 1,2,3-triazoles and evaluation of their fungicidal, phytotoxic, and antiproliferative activities
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Herein, the synthesis of nine novel glycerol-derived 4-alkyl-substituted 1,2,3-triazoles, using the CuI-catalyzed alkyne-azide cycloaddition reaction as the key step, is reported. The triazoles were characterized by infrared and nuclear magnetic resonance (NMR 1H and 13C) spectroscopy and mass spectrometry. The nine prepared compounds were evaluated with regard to their phytotoxic, antiproliferative, and fungicidal activities. The fungicidal activity was assessed on Colletotrichum gloeosporioides, the causative agent of papaya anthracnose. All compounds presented high efficiency (comparable to the commercial fungicide tebuconazole) in inhibiting C. gloeosporioides sporulation. The phytotoxicity of the triazoles was assessed against Lactuca sativa. Germination was the less-affected parameter, whereas the most pronounced effects of the triazoles were on the germination speed index and root growth of the L. sativa seedlings. As indicators of antiproliferative activity, the mitotic index was evaluated along with chromosomal and nuclear alterations, all of which were influenced to different degrees by the triazoles. In addition, all derivatives demonstrated aneugenic and clastogenic actions in meristematic cells of L. sativa roots. Therefore, these 4-alkyl-substituted triazoles may represent a scaffold to be explored for the development of new fungicidal agents.
- Costa, Adilson V.,Moreira, Luiza C.,Pinto, Roberta T.,Alves, Thammyres A.,Schwan, Vitor V.,de Queiroz, Vagner T.,Pra?a-Fontes, Milene M.,Teixeira, Róbson Ricardo,Morais, Pedro A.B.,de Jesus, Waldir C.
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- Surface-functionalized mesoporous gallosilicate catalysts for the efficient and sustainable upgrading of glycerol to solketal
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Two series of functionalized mesoporous Ga silicates were prepared in a straightforward and sustainable one-pot procedure using different alkyl silanes. The efficacy of the adopted co-synthetic approach based on aerosol processing has been proved by 29Si solid-state NMR experiments revealing a degree of functionalization close to the theoretical value. The successful incorporation of gallium as single sites within the silica framework was confirmed via71Ga solid-state magic-angle-spinning NMR measurements. These materials were tested as catalysts for the synthesis of solketal from glycerol at low temperature and under solventless conditions. A systematic study evidenced the importance of a careful tuning of surface polarity, achievable with surface functionalization as well as with different thermal treatments. The solids functionalized with a low degree of methyl groups (5%) displayed enhanced performances compared to the non-functionalized analogues, highlighting the highly beneficial role of surface hydrophobicity as well as the importance of the careful tuning of the hydrophilic/hydrophobic balance. The best functionalized catalysts proved to be easily reusable for multiple catalytic runs. With such a high-performance catalyst in hand, we propose a process which shows a favorable E-factor, indicating that the production of solketal can be envisaged in a sustainable way.
- Vivian, Alvise,Soumoy, Loraine,Fusaro, Luca,Fiorilli, Sonia,Debecker, Damien P.,Aprile, Carmela
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- Preparation of high-octane oxygenate fuel components from plant-derived polyols
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The ketalization of polyols (glycerol, xylitol, xylose) in the presence of a number of heterogeneous acid catalysts has been studied. It has been shown that zeolite catalysts exhibit high activity in the formation of the acetone ketal of glucose in a flow system with the quantitative selectivity for the 1,2-product. The best catalyst is zeolite β in the presence of this zeolite and excess acetone, the yield is over 90% or, in the case of the structured reactor, even greater than 98% It has been shown that zeolite-based systems catalyze the formation of ketals of xylitol and xylose with a yield of up to 50% in the presence of excess acetone.
- Maksimov,Nekhaev,Ramazanov,Arinicheva,Dzyubenko,Khadzhiev
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- A green approach for the preparation of a surfactant embedded sulfonated carbon catalyst towards glycerol acetalization reactions
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The green synthesis of heterogeneous catalysts often requires a solid-state reaction pathway. In this work, a cationic surfactant (CTAB) embedded sulfonated carbon catalyst was prepared via a sustainable route with the aim of having controlled surface hydrophobicity and acidity for glycerol acetalization reactions. The main objective of this study was to tune the hydrophobicity and acidic site density, either via adding a cationic surfactant or changing the carbon to sulphur ratio. The as-synthesized catalyst was characterized via XRD, N2 adsorption/desorption, SAXS, FESEM, FTIR, pyridine-IR, high-temperature DR-FTIR, TGA, 13C-NMR, Raman, and XPS techniques. The incorporation of a cationic surfactant (CTAB) reduces the surface area but increases the acidic site density to a greater extent. The bonding between the surfactant (CTAB) and surface hydroxyl groups was elucidated via XPS analysis. DR-FTIR studies implied that the -SO3H groups are strongly bonded to the carbon network, while the lower amount of water mass loss seen from TGA studies showed the substantial improvement in surface hydrophobicity after modification with the surfactant. Moreover, the combination of acidic site density and hydrophobicity played a key role in attaining around 90% glycerol conversion and 98% solketal selectivity under ambient conditions. Notably, characterization of the used catalyst revealed that the loss of activity is mainly related to a drop in hydrophobicity, which occurs due to the loss of surfactant during washing with methanol.
- Auroux, Aline,Chowdhury, Biswajit,Das, Avik,Ghosh, Anindya,Sen, Debasis,Singha, Aniruddha
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- Synthesis of biodiesel without formation of free glycerol
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A new approach to the synthesis of biodiesel has been developed on the basis of alcoholysis of a triglyceride in combination with acetalization of glycerol with lower carbonyl compounds or acetals derived therefrom. A model synthesis of biodiesel not involving free glycerol has been accomplished using rapeseed oil and acid catalysts, as well as without a catalyst under generation of ethanol supercritical fluid; in the latter case, monoalkyl glycerol ethers are formed in addition to the expected cyclic ketals.
- Vol'eva,Belostotskaya,Komissarova,Koverzanova,Kurkovskaya,Usmanov,Gumerov
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- Technologies for Processing of Crude Glycerol from Biodiesel Production: Synthesis of Solketal and Its Hydrolysis to Obtain Pure Glycerol
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Information on the volume of production of biodiesel and crude glycerol is discussed. The possibility of using crude glycerol as a feedstock for preparing solketal is demonstrated. The specific features of the solketal synthesis from crude glycerol and of separation of the reaction products are described. A catalytic process is suggested for selective decomposition of solketal to glycerol to obtain purified glycerol of any required concentration up to 99.8 wt.%. A flowsheet is provided for processing of crude glycerol to obtain solketal and subsequently converting it to obtain pure glycerol.
- Dmitriev,Zanaveskin,Terekhov,Samoilov,Kozlovskii,Maksimov
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- Enzymatic enantioselective ester hydrolysis by carboxylesterase NP
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The enzymatic hydrolysis of a series of carboxylic esters by carboxylesterase NP has been investigated in order to determine the scope and limitations of this enzyme. 2-Substituted propionates were hydrolyzed with high enantioselectivity when an aromatic moiety was part of the 2-substituent.Enantioselective hydrolysis could be accomplished with several 2-arypropionates, 2-(aryloxy)propionates and N-arylalanine esters.The propionate esters yielded propionic acids as (S) enantiomers, whereas the alanine esters yielded the (R) enantiomers.Without a 2-aryl substituent, the enzymatic hydrolysis of the propionates occurred at a lower rate without acceptable enantioselectivity.In addition to 2-substituted propionates, only a few other esters were hydrolyzed with high enantioselectivity by carboxylesterase NP, such as some prochiral disubstituted malonates. 1-Phenylethylacetate was the only substrate with chirality in the alcohol part of the ester that was found to be hydrolyzed enantioselectively.Carboxylesterase NP proved to be a powerful enzyme for kinetic resolution of propionate esters with an aromatic ring containing a 2-substituent.
- Smeets, J. W. H.,Kieboom, A. P. G.
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- New approach to the synthesis of 1,3-dioxolanes
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Application of ethanol to the synthesis of 1,3-dioxolanes by the condensation of carbonyl compounds with vicinal diols results in a high yield of the reaction product and considerably reduces the duration of the process. It is assumed that the effect of the ethanol is caused by the adduct formation with carbonyl compounds (hemiacetals) which behave as active intermediates of the condensation. A cyclic ketal of acetone with glycerol obtained with the help of ethanol was used as a basis component in the synthesis of a series of ketals substituting diol or carbonyl components by transketalyzation mechanism proceeding without water liberation.
- Vol'Eva,Belostotskaya,Malkova,Komissarova,Kurkovskaya,Usachev,Makarov
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- Water-soluble meroterpenes containing an aminoglyceride fragment with geraniol residues: synthesis and membranotropic properties
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A number of new membrane anchors based on water-soluble aminoglycerides with geraniol fragments have been synthesized. A biomimetic approach was used based on the design of meroterpenes structurally similar to archaeal lipids. Turbidimetry and laser Doppler microelectrophoresis showed that the synthesized compounds were incorporated into unilamellar dipalmitoylphosphatidylcholine (DPPC) vesicles.
- Akhmedov, Alan A.,Shurpik, Dmitry N.,Plemenkov, Vitaliy V.,Stoikov, Ivan I.
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- Highly Efficient Glycerol Acetalization over Supported Heteropoly Acid Catalysts
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The acetalization of glycerol with acetone to yield solketal was catalyzed by Cs2.5H0.5PW12O40 (Cs2.5) supported on mesoporous silica under mild conditions. It gave a high glycerol conversion and selectivity to the targeted product even at room temperature (23 °C). We studied the use of both bulk and supported Cs2.5 as catalysts in another highly efficient glycerol acetalization reaction with paraformaldehyde, which gave much higher activity than with formaldehyde solution. For the reaction with acetone, the supported Cs2.5 showed a higher activity than the bulk material because of the high surface area of the mesoporous support. Interestingly, the supported Cs2.5 gave a lower conversion than the bulk for the reaction with paraformaldehyde. This is probably because of the high viscosity of the reaction system with the solid reagent paraformaldehyde. Overall, there is a complex relationship between catalyst, reaction conditions, which include the molar ratio of reactants and temperature, reaction mechanism and thermodynamics that affects the achieved activity and byproduct formation. A discussion about these interactions is included for each reaction.
- Chen, Lin,Nohair, Bendaoud,Zhao, Dongyuan,Kaliaguine, Serge
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- Nano porous hydroxyapatite as a bi-functional catalyst for bio-fuel production
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Nano porous hydroxyapatite possessing acid-base functionality has been successfully synthesized by a simple hydrothermal method using P123 tri-block co-polymer as a structure directing agent. The material exhibited excellent catalytic activity for the production of solketal (100% selectivity) from bio-glycerol (90% conversion).
- Viswanadham, Nagabhatla,Debnath, Suman,Sreenivasulu, Peta,Nandan, Devaki,Saxena, Sandeep K.,Al-Muhtaseb, Ala'a H.
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- Design of highly efficient Mo and W-promoted SnO2 solid acids for heterogeneous catalysis: Acetalization of bio-glycerol
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Development of highly promising solid acids is one of the key technologies to meet the essential challenges of economical and environmental concerns. Thus, novel molybdenum and tungsten promoted SnO2 solid acids (wet-impregnation) and pure SnO2 (fusion method) were prepared. The synthesized catalysts were systematically analyzed using various techniques, namely, XRD, BET surface area, pore size distribution, XPS, FTIR, FTIR of adsorbed pyridine, Raman, NH3-TPD, and H2-TPR. XRD results suggested formation of nanocrystalline SnO2 solid solutions due to the incorporation of molybdenum and tungsten cations into the SnO2 lattice. All the materials exhibited smaller crystallite size, remarkable porosity, and high specific surface area. Raman measurements suggested the formation of more oxygen vacancy defects in the doped catalysts, and the TPR results confirmed facile reduction of the doped SnO2. NH 3-TPD studies revealed the beneficial role of molybdenum and tungsten oxides on the acidic properties of the SnO2. FTIR studies of adsorbed pyridine showed the existence of a larger number of Bronsted acidic sites compared to Lewis acidic sites in the prepared catalysts. The resulting catalysts are found to be efficient solid acids for acetalization of glycerol with acetone, furfural, and its derivatives under solvent-free and ambient temperature conditions. Particularly, the Mo6+-doped SnO 2 catalyst exhibited excellent catalytic performance in terms of both glycerol conversion and selectivity of the products. The increased presence of acidic sites and enhanced specific surface area, accompanied by notable redox properties and superior lattice defects are found to be the decisive factors for better catalytic activity of the Mo6+-doped SnO2 sample. The investigated SnO2 solid acids represent a novel class of heterogeneous catalysts useful for the transformation of glycerol to value-added products in an eco-friendly manner.
- Mallesham, Baithy,Sudarsanam, Putla,Raju, Gangadhara,Reddy, Benjaram M.
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- Solketal synthesis from ketalization of glycerol with acetone: A kinetic study over a sulfated zirconia catalyst
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In this work, a series of acid catalysts were synthetized from a commercial zirconium oxide sulfated with a 0.5 M H2SO4 solution by wet impregnation. The characterization results show a correlation between the calcination temperature and the acid sites generated on the materials. Among the catalysts prepared, the sulfated zirconia calcined in air at 400 °C (Zr-S-400), with a molar ratio S/Zr = 0.23 was the most active one due to its larger acid density and greater acid strength caused by the generation of new Br?nsted sites. The Zr-S-400 catalyst exhibited an initial reaction rate of 0.0497 mol.min?1. g?1, and achieved a glycerol conversion of 80 % in 1 h of reaction at 40 °C (glycerol:acetone molar ratio = 1:6). The Zr-S-400 material remained stable after four catalytic cycles, demonstrating the stability of the superficial sulfate species (S/Zr ～ 0.2). In addition, the thermodynamics and kinetics of the reaction were evaluated, as well as the influence of some operating conditions such as the molar ratio of reactants and the water content in the reaction mixture. The following standard molar reaction properties were obtained: ΔHo = -11.6 ± 1.1 kJ.mol?1 and ΔGo = 4.0 ± 0.1 kJ.mol?1. Taking into account that the adsorption of water on this catalyst did not affect the number of acid sites available, a simple pseudo-homogeneous kinetic expression was developed and successfully adjusted to the experimental data in the range under study. Based on this model, the estimated activation energy of the reaction was 88.1 ± 8.9 kJ.mol?1.
- Vannucci, Julián A.,Nichio, Nora N.,Pompeo, Francisco
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- Synthesis and properties of new fullerene C60 derivatives, containing acetonide and polyol fragments
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New mono- and hexa-methanofullerenes containing different number of acetonide groups are synthesized and characterized. Removing the acetonide protection leads to new chromatographically pure water-soluble polyol methanofullerenes with essentially quantitative yields.
- Gilmutdinova, Alina A.,Gubskaya, Valentina P.,Fazleeva, Guzel M.,Latypov, Shamil K.,Zhelonkina, Tatyana A.,Sharafutdinova, Dilara R.,Nuretdinov, Ildus A.,Sinyashin, Oleg G.
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- Ketalization of glycerol with acetone to o-heterocyclic compounds over ZrO2-SiO2 solid acid catalysts
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The solid acid catalysts ZrO2-SiO2 mixed oxides were prepared by sol-gel, characterized by X-ray diffraction, NH3-temperature programmed desorption, fourier transform infrared spectroscopy, and applied in the glycerol catalytic ketalization with acetone to O-heterocyclic compounds in the present work. Simultaneously, the effects of the catalysts composition, calcination temperature and ketalization parameters such as reaction time, acetone/glycerol, catalyst amount and reaction temperature on the ketalization were also investigated in detail. The results showed that the main product for the glycerol ketalization with acetone was solketal with a 5-membered ring along with a small amount of 2,2-dimethyl-1,3-dioxan-5-ol with a 6-membered ring. ZrO2-SiO2 with a Zr/Si molar ratio of 0.5 calcined at 500 °C exhibited the best catalytic property in ketalization, gave 90.91% of glycerol conversion and 89.69% of solketal selectivity under the optimum conditions. It was also found that glycerol catalytic ketalization with acetone to solketal was mainly governed by kinetics.
- Fan, Chunni,Xu, Chenghua,Liu, Chuanqi,Huang, Zunyu,Liu, Jianying,Ye, Zhixiang
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- Ga-MCM-41 nanoparticles: Synthesis and application of versatile heterogeneous catalysts
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Ga-MCM-41 materials with nanosized particles (2-physisorption, TEM, SEM and EDX, while 71Ga MAS-NMR was employed to monitor the coordination of the gallium atoms. The two materials were tested as heterogeneous catalysts in three relevant reactions in the context of green production of valuable chemicals: (1) the reaction of glycerol with acetone to produce solketal; (2) the conversion of the triose sugar dihydroxyacetone to ethyl lactate; (3) the epoxidation of cyclooctene with aqueous hydrogen peroxide. The two nanosized Ga-MCM-41 materials show different catalytic behaviour in the various reactions, with the material prepared with lower Si/Ga displaying a higher versatility. This catalyst reaches higher turnover numbers compared to conventional Ga-MCM-41 reported in the literature. This result is ascribed to the higher specific surface area and to the shorter channels of the nanoparticles, which enhance the accessibility of the active sites.
- Collard, Xavier,Li, Li,Lueangchaichaweng, Warunee,Bertrand, Arnaud,Aprile, Carmela,Pescarmona, Paolo P.
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- APPLICATION OF LIPASES IN THE REMOVAL OF PROTECTIVE GROUPS ON GLYCERIDES AND GLYCOSIDES
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Enzymatic hydrolysis of differently substituted carbohydrates with lipase from porcine pancreas and Candida cylindracea has been investigated.Selective removal of a n-butylryl group in the presence of an acetyl ester ( e.g. 16 17) and t-butylcarbonyl ester (e.g. 18 19) was feasible with lipase from Candida cylindracea.
- Kloosterman, M.,Mosmuller, E. W. J.,Schoemaker, H. E.,Meijer, E. M.
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- Solketal Formation in a Continuous Flow Process over Hierarchical Zeolites
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Glycerol ketalization with acetone to solketal, an oxygenate fuel additive, was demonstrated over hierarchical zeolites of ZSM5, Beta and Mordenite structure in a continuous flow system. Micro-mesoporous zeolites were prepared in two steps, by means of alkaline treatment with NaOH followed by the ionic exchange with NH4NO3 and a subsequent treatment with citric acid. The presence of mesopores in the applied catalysts was confirmed by N2 adsorption/desorption measurements and TEM microscopy. Hierarchical zeolites showed superior catalytic performance and lifetime over 24 hours under mild conditions (atmospheric pressure, acetone to glycerol molar ratio of 3 : 1, WHSV of 3–8 h?1, reaction temperature of 323 K). Glycerol conversion of about 90 % and selectivity to solketal up to 98 % have been obtained over micro-mesoporous catalysts within 24 h without any drop of performance and the symptoms of clogging. Among all hierarchical catalysts tested in a flow reactor, the very high activity defined as solketal yield (88 %) showed ZSM5 and Beta zeolites.
- Kowalska-Ku?, Jolanta,Held, Agnieszka,Nowińska, Krystyna
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- Al-SBA-15 catalysed cross-esterification and acetalisation of biomass-derived platform chemicals
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Al-SBA-15 exhibited excellent catalytic activities in acid-catalysed glycerol transformation including esterification and acetalisation reactions. Quantitative conversion and good selectivities to mono- and diacetylglycerides could be obtained in the esterification of glycerol with levulinic acid. The catalyst also proved to be very effective in the acetalisation of glycerol with aldehydes and acetone, with an interesting selectivity switch from the 6-membered acetal (using paraformaldehyde as an aldehyde source) to a 5-membered acetal (when benzaldehyde or furfural was employed). Al-SBA-15 materials were also proved to be highly stable and reusable in most glycerol transformations under the investigated reaction conditions.
- Gonzalez-Arellano, Camino,Arancon, Rick A. D.,Luque, Rafael
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- Interaction of triols with formaldehyde and acetone: Experimental and theoretical study
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Experimental and theoretical aspects of the condensation of glycerol and its homologs (1,2,3- and 1,2,4-butanetriols) with formaldehyde and acetone are studied under conditions of acid catalysis. Calculation of the thermodynamic parameters of the resulting products by the composite method CBS-QB3 shows that the six-membered heterocycles, the products of the interaction of triols with formaldehyde, are thermodynamically more stable than the five-membered acetals, while the reaction of the same triols with acetone is preferable for the formation of the five-membered acetals. This is due to the fact that the regioselectivity of the studied reactions is determined by the structural features and reactivity of the carbocations formed in a condensed medium during the course of the reaction. According to the theoretical data obtained experimentally, during the condensation of glycerol and 1,2,4-butanetriol with formaldehyde in the most stable form of the six-membered cyclic carbocation, intramolecular hydrogen bonding and anomeric stabilization due to the axially oriented hydroxyl group take place. As a result, cation 1b–1 is 1.2–1.6 kJ/mol more stable than its five-membered isomers (1a–1 and 1b–2). It leads to the predominant formation of 1,3-dioxane (3b). However, upon condensation of butanetriol-1,2,3 with formaldehyde, the intermediate cation 4a–1 turns out to be significantly more stable than the other isomers due to the strong intramolecular hydrogen bond in the six-membered ring with the participation of the hydroxyl group of the substituent and the hydroxyl group of the cationic center, leading to the predominant formation of the dioxolane 6a.
- Sultanova, Rimma,Borisevich, Sophia,Raskil'dina, Gulnara,Borisova, Julianna,Baykova, Irina,Spirikhin, Leonid,Khursan, Sergey,Zlotsky, Simon
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- Solvent-free conversion of glycerol to solketal catalysed by activated carbons functionalised with acid groups
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Activated carbons prepared from agricultural waste were modified to introduce surface acid sites by treatment with HNO3 or H 2SO4. These acid-functionalised materials were studied as heterogeneous catalysts for the solvent-free acetalisation of acetone with glycerol to produce 2,2-dimethyl-1,3-dioxolane-4-methanol (solketal). The best catalyst was prepared by treatment with concentrated sulphuric acid and achieved 97% conversion of glycerol with high selectivity towards solketal by reaction with acetone at room temperature. The catalytic behaviour of the activated carbons was correlated with their physicochemical properties through characterization by N2-physisorption, XPS, elemental analysis, TGA and Boehm titration of the acid sites.
- Rodrigues, Raphael,Goncalves, Maraisa,Mandelli, Dalmo,Pescarmona, Paolo P.,Carvalho, Wagner A.
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- Mesoporous tin oxide: An efficient catalyst with versatile applications in acid and oxidation catalysis
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Mesoporous tin oxide was prepared by template assisted and template-free methods. As-prepared materials were calcined at various temperatures to generate different nature (Br?nsted and Lewis), amount and strength of acidic sites. The physico-chemical properties of the catalysts were studied by XRD, N2 sorption, pyridine-FTIR, NH3-TPD, DRS UV-vis, TGA, SEM, TEM, 1H MAS and 119Sn MAS NMR analyses. The catalytic behavior of mesoporous tin oxide catalysts was evaluated for acetalization and ketalization of glycerol with benzaldehyde and acetone respectively under solvent free conditions. The catalytic performance of mesoporous tin oxide was compared with that of other conventional solid acid catalysts namely H-ZSM-5, H-mordenite, H-beta, Al-MCM-41, Al-SBA-15 and Al-TUD-1. The efficiency of mesoporous tin oxide was also tested for cyclohexene epoxidation reaction. The catalyst prepared by template assisted method showed excellent catalytic performance compared to other catalysts due the difference in nature and amount of acidic sites in the catalyst. Meso-SnO2-T-350 was stable and reusable catalyst for four cycles without any appreciable loss in activity, and therefore it offers a good catalyst for potentially wide applications.
- Manjunathan, Pandian,Marakatti, Vijaykumar S.,Chandra, Prakash,Kulal, Atul B.,Umbarkar, Shubhangi B.,Ravishankar, Raman,Shanbhag, Ganapati V.
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- Site-specific 2H-labeled oleic acid and derived esters for use as tracers of ethyl oleate metabolism in honey bees
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The inventory of labeled fatty acids and protocols for their syntheses are constantly increasing, but site-specific labeled precursors in biosynthetic studies are still needed. Ethyl oleate (EO) is an important primer pheromone in honeybees, which is responsible for the regulation of behavioral maturation. During our biosynthetic studies on EO, a site-specific labeled oleic acid precursor was required. In this report, a synthetic route adaptable to the preparation of [9,10,11,11-D4] oleic acid and its derived esters for use as tracers of EO metabolism in honey bees is presented. Copyright
- Chen, Hao,Plettner, Erika
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- Exploring the Br?nsted acidity of UiO-66 (Zr, Ce, Hf) metal-organic frameworks for efficient solketal synthesis from glycerol acetalization
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Zr, Ce, Hf-based isostructural UIO-66 MOFs exhibited varying degree of Br?nsted acidity (UiO-66(Hf) > UiO-66(Ce) > UiO-66(Zr)) on their secondary building units owing to the differences in their oxophilicities. UIO-66(Hf) showed remarkable catalytic activity for solketal synthesis with a turnover frequency as high as 13?886 h?1, which is 90 times higher than that of UiO-66(Zr) and several orders of magnitude higher than that of H2SO4 or Zeolites.
- Bakuru, Vasudeva Rao,Churipard, Sathyapal R.,Maradur, Sanjeev P.,Kalidindi, Suresh Babu
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- Synthesis and immunological study of a wall teichoic acid-based vaccine against E. faecium U0317
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A repeat unit of cell wall teichoic acids (WTA) isolated from E. faecium U0317 was chemically synthesized efficiently by a stepwise strategy. It was derivatized with a 5-aminopentanyl linker to facilitate conjugation with carrier proteins KLH and HSA. Immunological studies of the KLH conjugate 1 demonstrated that it could provoke robust immune responses and high titers of IgG antibodies, which could successfully recognize the synthesized WTA repeat unit 3. This result suggested that synthetic glycoconjugate 1 could be a promising vaccine candidate against E. faecium for further studies.
- Zhou, Zhifang,Ding, Wenzhang,Li, Chen,Wu, Zhimeng
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- Acetalization of glycerol with ketones and aldehydes catalyzed by high silica Hβ zeolite
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In this work, proton-exchanged *BEA zeolite with a high Si/Al ratio of 75 (Hβ-75), was demonstrated as an effective catalyst for the acetalization of glycerol with carbonyl compounds. This catalyst system was applicable to various substrates and reusable for at least 4 times with slight decrease in activity. The turnover frequency, based on acid site concentration, increased as a function of Hβ Si/Al ratio, indicating the importance of the zeolite hydrophobic surface properties. The origin of the high efficiency exhibited by Hβ-75 is quantitatively discussed based on kinetic studies, hydrophobicity, and acid site concentration.
- Poly, Sharmin Sultana,Jamil, Md.A.R.,Touchy, Abeda S.,Yasumura, Shunsaku,Siddiki, S.M.A. Hakim,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-ichi
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- Highly-efficient conversion of glycerol to solketal over heterogeneous Lewis acid catalysts
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The acetalization of acetone with glycerol to yield 2,2-dimethyl-1,3- dioxolane-4-methanol (solketal) was successfully catalyzed by mesoporous substituted silicates including the novel Hf-TUD-1 material. This reaction offers an attractive path for the conversion of glycerol, which is the main side-product in the synthesis of biodiesel, to a valuable compound with potential for industrial applications. The most promising among the heterogeneous catalysts employed in this work, Zr- and Hf-TUD-1 and Sn-MCM-41, display mainly Lewis acid properties as demonstrated by characterization with FT-IR analysis of pyridine adsorption, and achieve superior results compared to a reference solid acid catalyst such as Ultrastable zeolite Y. Especially the newly synthesized Hf-TUD-1, showing the highest conversion and turnover among the screened materials, is a promising catalyst for the acetalization of acetone with glycerol in a sustainable process. The excellent performance of these mesoporous catalysts is ascribed to their combination of acidity, wide pores, large specific surface area and relatively hydrophobic surface. The Royal Society of Chemistry.
- Li, Li,Koranyi, Tamas I.,Sels, Bert F.,Pescarmona, Paolo P.
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- Continuous reactor technology for ketal formation: An improved synthesis of solketal
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The development of a fully continuous process for the synthesis of solketal (4-hydroxymethyl-2,2-dimethyl-1,3-dioxolane) is described. The use of a heterogeneous catalyst, recycle of unreacted starting material, elimination of the need for an entraining solvent, and purification of the product in situ all afford improvements over existing processes. Data generated in model reactions is used to prove the applicability of the process to a counter-current distillation reactor design, and to compute the operating parameters of the reactor.
- Clarkson, Jay S.,Walker, Andrew J.,Wood, Michael A.
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- Carbonized glycerol nanotubes as efficient catalysts for biofuel production
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Highly acidic, functionalized, carbonized glycerol nanotubes successfully synthesized via a simultaneous carbonization and acidification have been identified as efficient and stable solid acid catalysts for biofuel production from glycerol and levulinic acid.
- Viswanadham, Nagabhatla,Debnath, Suman,Saxena, Sandeep K.,Al-Muhtaseb, Ala'A H.
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- Dealuminated BEA zeolite for selective synthesis of five-membered cyclic acetal from glycerol under ambient conditions
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BEA zeolite was treated with phenoldisulfonic acid (PDSA) of different concentrations from 0.1 M to 1.0 M to obtain dealuminated zeolites. The treated BEA samples were characterized by XRD, 27Al-MAS NMR, SEM-EDX, TPD NH3, pyridine-FTIR and BET measurements. Modified zeolites showed an increase in surface area and pore volume and a decrease in acid amount with an increase in PDSA concentration. An untreated BEA sample catalyzed the reaction between glycerol and acetone to form glycerol acteals to yield two products, five-membered dioxalane and six-membered dioxane. Under optimized reaction conditions, the untreated BEA sample showed 83% dioxalane and 17% dioxane while the modified samples showed an increase in dioxalane selectivity with an increase in the acid concentration used for the treatment. The 1 M PDSA treated sample exhibited 100% selectivity for dioxalane. This is attributed to an increase in pore volume and decrease in acid amount of the modified BEA samples with an increase in PDSA concentration. The combined effect of pore volume and acidity in determining dioxalane selectivity is discussed.
- Venkatesha,Bhat,Jai Prakash
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- Synthesis of ethers and cyclic acetals in the presence of CBV-720 zeolite
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СBV-720 zeolite was compared to H-Beta zeolite and KU-2 cation-exchange resin in the catalytic performance in addition of alcohols to norbornene, in condensation of aldehyde and ketone with di- and triols, and in the Prins reaction of olefins with formaldehyde. These reactions, when performed on СBV-720 zeolite, occur 1.5–2 times faster than on the other catalysts. The corresponding ethers and cyclic acetals were synthesized.
- Baiburtli,Raskil’dina,Zlotskii
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- Acetalization of acetone with glycerol catalyzed by niobium-aluminum mixed oxides synthesized by a sol–gel process
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Niobium-aluminum-based catalysts were synthesized by a sol–gel process and successfully applied to the reaction of acetalization of acetone with glycerol yielding 2,2-dimethyl-1,3-dioxolane-4-methanol (solketal) and 2,2-dimethyl-1,3-dioxan-5-ol. The synthesis procedure was developed using high-throughput techniques and the materials prepared with molar ratio1 Metal (1Nb:xAl): 100H2O: 1.5NH4OH (in which x?=?1, 0.6, 0.3, 0.1 and 0.05) were selected to be further investigated. The obtained series of mixed oxides displayed high catalytic activity reaching glycerol conversion up to 84%, with 98% of selectivity towards solketal. The physicochemical properties of the investigated catalysts were characterized by N2-adorption/desorption, thermal analysis, X-rays diffraction, FTIR and Raman spectroscopy, and by adsorption of pyridine monitored by FT-IR spectroscopy and TGA. The catalysts are truly heterogeneous and can be reused in consecutive runs without loss of activity.
- Rodrigues, Raphael,Mandelli, Dalmo,Gon?alves, Norberto S.,Pescarmona, Paolo P.,Carvalho, Wagner A.
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- Synthesis of acetonides from epoxides catalyzed by erbium(III) triflate
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Epoxides dissolved in acetone can be converted almost quantitatively in acetonides in the presence of catalytic amounts of erhium(III) triflate. The procedure can be usefully applied to other substrates and can be extended to other ketones.
- Procopio, Antonio,Dalpozzo, Renato,De Nino, Antonio,Maiuolo, Loredana,Nardi, Monica,Russo, Beatrice
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- Water-tolerant zeolite catalyst for the acetalisation of glycerol
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We studied the acid-catalysed reaction of glycerol with aqueous formaldehyde and acetone in absence of solvents and using heterogeneous catalysts. The reactivity of acetone was usually higher than formaldehyde and the glycerol conversion was over 90% within 40 min of reaction time for all the heterogeneous acid catalysts studied. With aqueous formaldehyde solution, the glycerol conversion was within 60 to 80%, depending upon the acid catalyst used (Amberlyst-15, K-10 montmorillonite, p-toluene-sulfonic acid), due to the high amount of water in the reaction medium, which shifts the equilibrium and weakens the acid sites. However, the use of zeolite Beta, with Si/Al ratio of 16, leads to a conversion of over 95% within 60 min of reaction time. The hydrophobic character of the zeolite, due to the high silicon content, prevents the diffusion of the water to the interior of the pore, preserving the strength of the acid sites. In addition, the water formed during the acetalisation is expelled off from the pore environment, impairing the reverse reaction, and avoiding the use of hazard solvents, commonly employed to distil off the water formed.
- Da Silva, Carolina X. A.,Gonalves, Valter L. C.,Mota, Claudio J. A.
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- Ru(III) catalyses the conversion of epoxides to 1,3-dioxolanes
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Anhydrous RuCl3 catalyses the efficient reaction of epoxides with acetone to give the corresponding 1,3-dioxolanes in high yields.
- Iranpoor,Kazemi
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- Kinetics of the Formation of Solketal in the Presence of Sulfuric Acid
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The kinetics of reversible solketal synthesis in the presence of sulfuric acid as a catalyst is studied. The parameters of kinetic equations describing direct and reverse reactions are found.
- Dmitriev,Terekhov,Zanaveskin,Maksimov,Khadzhiev
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- Creation of Bronsted acid sites on Sn-based solid catalysts for the conversion of biomass
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Hydroxyl-attached Sn species are highly dispersed on the surface of mesoporous silica (SBA-15) by the grafting of dimethyldichlorostannane followed by calcination to transform the methyl groups into hydroxyl groups (S-Sn-OH). S-Sn-OH has both Lewis and Bronsted acidic sites, resulting in superior catalytic activities in the acetalisation of glycerol.
- Wang, Liang,Zhang, Jian,Wang, Xuefeng,Zhang, Bingsen,Ji, Weijie,Meng, Xiangju,Li, Jixue,Su, Dang Sheng,Bao, Xinhe,Xiao, Feng-Shou
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- Amino acid ionic liquids as catalysts in a solvent-free Morita-Baylis-Hillman reaction
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In the present work, we describe the preparation of ten amino acid ionic liquids (AAILs) formed from ammonium salts as cations, derivatives of glycerol, and natural amino acids as anions. All of them are viscous oils, colorless or pale yellow, and hygroscopic at room temperature. They have appreciable solubility in many protic and aprotic polar solvents. The AAILs were used as catalysts in a Morita-Baylis-Hillman (MBH) reaction. The ionic liquids derivative from l-proline and l-histidine demonstrated the ability to catalyze the reaction between methyl vinyl ketone and aromatic aldehydes differently substituted in the absence of an additional co-catalyst under organic solvent-free conditions. The AAIL derivatives from l-valine, l-leucine, and l-tyrosine catalyzed the MBH reaction only in the presence of imidazole. The MBH adducts were obtained in moderate to good yields. Although the catalytic site in the ILs was in its enantiomerically pure form, all the MBH adducts were obtained in their racemic form.
- Pereira, Mathias Prado,Souza Martins, Rafaela De,De Oliveira, Marcone Augusto Leal,Bombonato, Fernanda Irene
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- Supramolecular assemblies of novel aminonucleoside phospholipids and their bonding to nucleic acids
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A novel class of aminonucleoside phospholipids has been developed. These molecules could spontaneously assemble into supramolecular structures including multilamellar organization, hydrogels, superhelical strands, and vesicles. Their ability to bind to DNA by hydrogen bonding and π-π stacking interactions was investigated by many means. This journal is
- Pan, Delin,Sun, Jing,Jin, Hongwei,Li, Yating,Li, Liyu,Wu, Yun,Zhang, Lihe,Yang, Zhenjun
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- Green efficient synthesis of ketal under catalysis of ionic liquid TTPT
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The invention discloses a method for green efficient synthesis of ketal under catalysis of ionic liquid TTPT. The method comprises the following steps: adding TTPT and a water-carrying agent into a raw material I and a raw material II, and carrying out a heating reflux reaction for 110-150 minutes, wherein R1 and R2 in formulas I and II are independently selected from a group consisting of a methyl group, an ethyl group and a phenyl group, or R1 and R2 are connected and cyclized to form a 5-to-10-membered naphthenic base; and R3 is selected from H or-OH. Compared with the prior art, the catalytic yield of the TTPT is remarkably improved, a good catalytic effect is achieved, and experimental operation is easy and convenient.
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Paragraph 0037-0040
(2021/08/07)
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- H2-Free Selective Dehydroxymethylation of Primary Alcohols over Palladium Nanoparticle Catalysts
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The dehydroxymethylation of primary alcohols is a promising strategy to transform biomass-derived oxygenates into hydrocarbon fuels. In this study, a novel, highly efficient, and reusable heterogeneous catalyst system was established for the H2-free dehydroxymethylation of primary alcohol using cerium oxide-supported palladium nanoparticles (Pd/CeO2). A wide range of aliphatic and aromatic alcohols including biomass-derived alcohols were converted into the corresponding one-carbon shorter hydrocarbons in high yields in the absence of any additives, accompanied by the production of H2 and CO. Pd/CeO2 was easily recovered from the reaction mixture and reused, retaining its high activity, thus, providing a simple and sustainable methodology to produce hydrocarbon fuels from biomass-derived oxygenates.
- Yamaguchi, Sho,Kondo, Hiroki,Uesugi, Kohei,Sakoda, Katsumasa,Jitsukawa, Koichiro,Mitsudome, Takato,Mizugaki, Tomoo
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p. 1135 - 1139
(2020/12/29)
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- Preparation method of trans-1, 3-diolefine
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The invention discloses a preparation method of trans-1, 3-diolefine, which comprises the following step: under the action of 4-dimethylaminopyridine and triethylamine, reacting 2, 3-dihydroxy propyl(9E, 12E)-9, 12-octadecadienoic acid ester with (9E, 12E)-9, 12-octadecadienoyl chloride to obtain the trans-1, 3-diolefine. Compared with the prior art, the method disclosed by the invention is simpleto operate, high in reaction selectivity and high in product yield.
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Paragraph 0068
(2021/03/18)
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- WAX EXPANSION AGENT AND WAX COMPOSITION CONTAINING THE SAME
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Provided is a wax expansion agent which, by being added in a very small amount to a wax, enables improvement of the coefficient of thermal expansion of the wax when the same has been heated. The wax expansion agent comprises a cyclic ether compound represented by formula (I). (In the formula, R1 represents a C11-C23 alkyl group.).
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Paragraph 0030-0031
(2021/02/05)
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- Fe doped aluminoborate PKU-1 catalysts for the ketalization of glycerol to solketal: Unveiling the effects of iron composition and boron
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An inexpensive Fe doped aluminoborate consisted of 18% Fe in PKU-1 material that exhibits high selectivity of 4-hydroxymethy-2,2-dimethyl-1,3-dioxolane (Solketal, 98.3%), considerable activity (TOF 51.7 h?1), and recyclable ability in the ketalization of glycerol to Solketal with acetone at 318 K has been developed. Our study demonstrated that the structure of Fe (less agglomerated iron species vs. FeOx clusters) can be tuned by changing Fe loading in the PKU-1 material, which correlated well with experimental observations. Furthermore, the surface boron sites were promoted by iron loading and behaved as Lewis-acid sites to facilitate the reaction process of glycerol ketalization, while the Solketal selectivity was closely related with the structure of iron species in PKU-1, which was proved by kinetic studies, density function theory (DFT) calculations, and a series of spectroscopy studies. This investigation demonstrates that the surface B sites can play important roles in the reaction instead of being spectators.
- Dang, Yanliu,Dong, Fan,He, Yang,Jiang, Guangming,Ouyang, Ping,Suib, Steven L.,Wang, Weilu,Yang, Tao,Zeng, Xiangke,Zhang, Haidong
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supporting information
(2021/10/29)
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- Structure–Activity Relationships of WOx-Promoted TiO2–ZrO2 Solid Acid Catalyst for Acetalization and Ketalization of Glycerol towards Biofuel Additives
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Abstract: WOx-promoted TiO2–ZrO2 solid acid catalyst was prepared and applied in the catalytic acetalization and ketalization of glycerol with carbonyl compounds to produce biofuel additives. The presence of WOx promoter and TiO2 remarkably improved the catalytic activity of ZrO2. Approximately, 100% glycerol conversion was evidenced with non-bulky aliphatic aldehydes and ketones like, propanol and cyclohexanone. The physical characterization of WOx-promoted TiO2–ZrO2, revealed a higher formation of tetragonal crystalline phase of ZrO2, over monoclinic. The total surface acidity and the ratio of Br?nsted to Lewis acidic site concentrations were determined by NH3-TPD and pyridine-chemisorbed FTIR spectroscopy, respectively. A considerably higher concentration of Lewis acidic sites, ~ 213.29?μmol/gm, was evidenced on the WOx-promoted TiO2–ZrO2 catalyst surface. Catalytic activity study revealed a direct correlation between the surface Lewis acidic site concentration and the activity of catalyst. This significant observation indicated the key role of Lewis acidic sites in this catalytic process. The WOx-promoted TiO2–ZrO2 catalyst was also considerably stable and showed good performance in the acetalization/ketalization of glycerol with other substituted carbonyl compounds. Graphic Abstract: The WOx-promoted TiO2–ZrO2 solid acid catalyst exhibits superior catalytic performance for acetalization and ketalization of glycerol with carbonyl compounds to produce biofuel additives. [Figure not available: see fulltext.].
- Baithy, Mallesham,Mukherjee, Deboshree,Rangaswamy, Agolu,Reddy, Benjaram M.
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- Method for preparing ketal glycerine and/or acetal glycerine by catalyzing glycerine
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The invention relates to a method for preparing ketal glycerine and/or acetal glycerine by catalyzing glycerine. The method comprises the following steps: contacting glycerine and a reaction raw material with a catalyst in a reactor, and reacting to obtain a product containing ketal glycerine and/or acetal glycerine, wherein the reaction raw materials contains aldehyde and/or ketone, the molar ratio of glycerine to aldehyde and/or ketone is 1:(1-10), the reaction temperature is 30-180 DEG C, the reaction time is 1-10 hours, the catalyst contains a tin-silicon molecular sieve, and the weight ratio of glycerine to the tin-silicon molecular sieve based on dry basis weight is (1-40):1, the tin-silicon molecular sieve contains a silicon element, a tin element and an oxygen element, a cavity orcavity structure is formed in all or part of crystal grains, the total specific surface area is larger than or equal to 300 m/g, and the proportion of the external specific surface area to the total specific surface area is larger than or equal to 10%. The method provided by the invention has high aldehyde/ketone conversion rate and high acetal/ketal glycerine selectivity.
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Paragraph 0152-0173; 0182-0187; 0193
(2020/07/02)
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- Short gram-scale synthesis of sulfavant A
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Recently, we reported the promising activity of a novel class of sulfoquinovosyl-diacylglycerols named Sulfavants as molecular vaccine adjuvants. Herein, we describe a modified and improved chemical synthesis of the lead product Sulfavant A (1), with the aim to produce from milligrams to 10 g of the pure compound that is necessary for the preclinical development. Starting from the versatile synthesis based on the trichloroacetimidate methodology, up-scaled preparation of Sulfavant A (1) was achieved in 11 steps by elimination and modification of those reactions that negatively affected the overall yield by the previous procedure. The novel strategy gave 17% overall yield of the target compound 1 and also paved the way for the gram-scale preparation of a wide range of other charged and neutral glycoglycerolipids.
- Ziaco, Marcello,Fioretto, Laura,Nuzzo, Genoveffa,Fontana, Angelo,Manzo, Emiliano
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p. 2728 - 2733
(2020/11/18)
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- Detergent-Like Polymerizable Monomers: Synthesis, Physicochemical, and Biochemical Characterization
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Three monomers with a maltose polar head, an alkyl hydrogenated chain, and an acrylamide-based polymerizable moiety were synthesized. The self-assembly properties in aqueous solutions of these monomers were studied by means of isothermal titration calorimetry (ITC), surface tension (SFT) measurements, and dynamic light scattering (DLS), which indicated the formation of small micellar aggregates of about 6 nm diameter. The critical micellar concentration (CMC) was found to depend on the length of the alkyl chain and on the nature of the polymerizable moiety, ranging from 0.35 mm to ca. 10 mm. The monomers were found to solubilize phospholipid vesicles and to extract a broad range of proteins from Escherichia coli membranes. Finally, the extraction of two membrane proteins, namely, the full-length, wild-type human G-protein-coupled receptor (GPCR) adenosine A2A receptor (A2AR) and the bacterial transporter AcrB was demonstrated.
- Bonnet, Christophe,Durand, Grégory,Guillet, Pierre,Igonet, Sébastien,Jawhari, Anass,Keller, Sandro,Mahler, Florian
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- A transesterification-acetalization catalytic tandem process for the functionalization of glycerol: The pivotal role of isopropenyl acetate
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At 30 °C, in the presence of Amberlyst-15 as a catalyst, a tandem sequence was implemented by which a pool of innocuous reactants (isopropenyl acetate, acetic acid and acetone) allowed upgrading of glycerol through selective acetylation and acetalization processes. The study provided evidence for the occurrence of multiple concomitant reactions. Isopropenyl acetate acted as a transesterification agent to provide glyceryl esters, and it was concurrently subjected to an acidolysis reaction promoted by AcOH. Both these transformations co-generated acetone which converted glycerol into the corresponding acetals, while acidolysis sourced also acetic anhydride that acted as an acetylation reactant. However, tuning of conditions, mostly by changing the reactant molar ratio and optimizing the reaction time, was successful to steer the set of all reactions towards the synthesis of either a 1?:?1 mixture of acetal acetates (97% of which was solketal acetate) and triacetin, or acetal acetates in up to 91% yield, at complete conversion of glycerol. To the best of our knowledge, a one-pot protocol with such a degree of control on the functionalization of glycerol via transesterification and acetalization reactions has not been previously reported. The procedure was also easily reproduced on a gram scale, thereby proving its efficiency for preparative purposes. Finally, the design of experiments with isotopically labelled reagents, particularly d4-acetic acid and d6-acetone, helped to estimate the contribution of different reaction partners (iPAc/AcOH/acetone) to the formation of final products. This journal is
- Calmanti, Roberto,Perosa, Alvise,Rigo, Davide,Selva, Maurizio
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p. 5487 - 5496
(2020/09/23)
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- The influence of PO4 to bio-silica catalyst on synthesis benign additive fuel
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FUEL product additive (glycerol) solketal and acetone. can be produced This reaction through was acetalization conducted over reaction acidified of silica biodiesel derived by-from sustainable bioresource rice husk in a batch reactor under the solvent-free condition. The chemical and structural properties of the prepared catalyst were studied by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), N2 adsorption/desorption isotherms, temperature-programmed desorption of ammonia (NH3-TPD) and scanning electron microscope (SEM). Based on this paper, the optimized conditions using 15% phosphoric acid acid ifiedsilica extracted from rice huskash (10 wt.% PO4 loaded SiO2) are 50°C (lower temperature) with the molar ratio of acetone: glycerol = 2. Reusability test used to examine the stability of the catalytic activity was investigated. This effort is a serious step for development and taking apart of solketal as the main product from glycerol and acetone by using waste resources.
- Radwan,Zaki,Abd El Salam,Aman
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p. 1541 - 1553
(2020/07/15)
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- PROCESSES FOR FORMING GLYCOLS
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This disclosure provides processes for forming glycols by upgrading hydrocarbons. In one embodiment, a process for forming a glycol includes introducing a first ether to a dihydrocarbyl peroxide to form a diether and a first alcohol. The process includes introducing the diether to water to form a glycol and a second alcohol. Processes of this disclosure may include one or more of: introducing a hydrocarbyl hydroperoxide to a third alcohol to form the dihydrocarbyl peroxide; oxidizing a first feed stream comprising a branched hydrocarbon to form the hydrocarbyl hydroperoxide and the first alcohol; and/or introducing the second alcohol to a catalyst to form a second ether.
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Paragraph 0095
(2020/05/28)
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- Preparation method of phosphatidylglycerol monosodium salt containing two different side chains
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The invention belongs to the technical field of compound preparation. The invention relates to a preparation method of phosphatidylglycerol monosodium salt, in particular to a preparation method of phosphatidylglycerol monosodium salt containing two different side chains. The preparation method comprises the following steps: taking D-mannitol as an initial raw material, heating D-mannitol in acetone to generate 1,1,5,6-isopropylidene-D-mannitol; carrying out sodium periodate oxidation and sodium borohydride reduction to obtain iso-propylidene glycerol; carrying out condensation reaction with fatty acid containing an R1 element, then removing acetal protective groups in the presence of acid; selectively protecting primary hydroxyl by using a silane protective agent, reacting secondary hydroxyl with another fatty acid containing a R2 element, removing silane protection, reacting the de-protected product with phosphorus oxychloride and iso-propylidene glycerol, removing acetal protectivegroups by using an acid, and finally carrying out a sodium salt treatment to obtain a final product. The synthesis of phosphatidyl monosodium salt containing two different side chains can be realized,and the production process is simple, environment-friendly and easy to operate.
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Paragraph 0045-0050
(2020/05/05)
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- Design and preparation of a novel prolinamide-based organocatalyst for the solvent-free asymmetric aldol reaction
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The preparation of four novel organocatalysts as highly diastereo and enantioselective catalysts for the solvent-free asymmetric aldol reaction was described. These organocatalysts were synthesized in eight steps applying simple and commercially available starting materials. The best results were obtained for the proline-derived catalyst, providing access to the desired adducts in up to 95% yield, 1:19 syn/anti and 98% e.e. Moreover, even sterically bulky aldehydes and substituted cyclohexanones were well tolerated. DFT calculations and control experiments indicated that several hydrogen bonding interactions between the aldehyde and the enamine intermediate are responsible for the stereoselective chiral induction process and that the trifluoroacetate counter-anion is crucial for the attainment of higher stereoselectivities.
- Martins, Rafaela de S.,Pereira, Mathias P.,de Castro, Pedro P.,Bombonato, Fernanda I.
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supporting information
(2019/12/24)
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- Synthesis of Highly Accessible Gallosilicates via Impregnation Procedure: Enhanced Catalytic Performances in the Conversion of Glycerol into Solketal
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Two mesoporous gallosilicates with extra-small particle size were synthesized via wet impregnation starting from lactate or citrate-type Ga(III) precursors. The structural and textural properties of the materials were extensively characterized by different techniques. Both materials consist of nanosized particles and display a remarkably high surface area and a pore size distribution typical of mesoporous MCM-41-like materials. The two solids were tested as catalysts in acetalization of glycerol with acetone to produce solketal (2,2-dimethyl-1,3-dioxolane-4-methanol). Both catalysts displayed excellent performances and achieved higher turnover numbers compared to other Ga-silicates reported in literature. The outstanding activity of these catalysts is attributed to the combination of acidity, large specific surface area as well as to the full accessibility of the active sites as consequence of the impregnation procedure. The best catalysts are truly heterogeneous with absence of Ga leaching and reusable in successive catalytic cycles after thermal treatment without significant deterioration of the catalytic performance.
- Aprile, Carmela,Devillers, Michel,Fusaro, Luca,Hussein, Hussein,Vivian, Alvise
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p. 5966 - 5976
(2020/12/07)
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- Solvent-free ketalization of polyols over germanosilicate zeolites: The role of the nature and strength of acid sites
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Isomorphic substitution of silicon for germanium affords germanosilicate zeolites with weak acid centers capable of catalyzing key reactions such as Baeyer-Villiger oxidation of ketones and etherification of levulinic acid. Herein, we show for the first time that UTL (Si/Ge = 4.2) and IWW (Si/Ge = 7.2) germanosilicate zeolites are active and selective catalysts of polyol (e.g., ethylene glycol, glycerol and 1,4 butanediol) ketalization to dioxolanes. Large-pore IWW outperformed the extra-large-pore UTL zeolite in the ketalization of polyols, thus indicating diffusion limitations in bulky platelet-like UTL crystals. FTIR spectroscopy of adsorbed pyridine revealed the Lewis acidity of the UTL zeolite, whereas the more active IWW catalyst was characterized by water-induced Br?nsted acidity. Increasing the activation temperature (200-450 °C) reduced the concentration of Br?nsted acid centers in the IWW germanosilicate (i.e., 0.16; 0.07 and 0.05 mmol g-1 for Tact = 200, 300 and 450 °C, respectively) but increased the number of Lewis acid sites in both zeolites. Under optimized reaction conditions (e.g., acetone/glycerol = 25, Tact = 300 °C), almost total transformation of glycerol into solketal was achieved within 3 h of reaction time over the IWW zeolite at room temperature (>99% yield of the target product). The results from the present study clearly show that weak acid centers of germanosilicate zeolites can serve as active sites in ketalization reactions.
- Podolean, Iunia,Zhang, Jin,Shamzhy, Mariya,Parvulescu, Vasile I.,?ejka, Ji?í
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p. 8254 - 8264
(2020/12/30)
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- Industrial preparation method of 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane
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The invention discloses an industrial preparation method of 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane. The industrial preparation method of the 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane comprises the steps that (1) carboxylic acid monoglyceride is prepared by esterification reaction, specifically, glycerol and carboxylic acid are used as raw materials, and under the condition of acidic catalyst,the dehydration reaction is carried out under the condition of 90-150 DEG C for 0.5-4h to obtain the carboxylic acid monoglyceride; (2) ketal cyclization reaction is carried out, specifically, the carboxylic acid monoglyceride and acetone are controlled to perform the cyclization reaction at 20-50 DEG C for 0.5-3 h under the condition of acid catalyst reaction to obtain a cyclization intermediateproduct; and (3) hydrolysis reaction is carried out, specifically, the intermediate product obtained in the step (2) is added into an alkaline solution, the mixture reacts for 0.5-1 h at 20-50 DEG C,and the 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane is obtained. The industrial preparation method of the 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane has the characteristics of green and environment-friendly process, high selectivity of industrial reaction and high conversion rate of raw materials.
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Paragraph 0044; 0046
(2019/06/13)
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- Total Synthesis of the Congested, Bisphosphorylated Morganella morganii Zwitterionic Trisaccharide Repeating Unit
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Zwitterionic polysaccharides (ZPSs) activate T-cell-dependent immune responses by major histocompatibility complex class II presentation. Herein, we report the first synthesis of a Morganella morganii ZPS repeating unit as an enabling tool in the synthesis of novel ZPS materials. The repeating unit incorporates a 1,2-cis-α-glycosidic bond; the problematic 1,2-trans-galactosidic bond, Gal-β-(1 → 3)-GalNAc; and phosphoglycerol and phosphocholine residues which have not been previously observed together as functional groups on the same oligosaccharide. The successful third-generation approach leverages a first in class glycosylation of a phosphoglycerol-functionalized acceptor. To install the phosphocholine unit, a highly effective phosphocholine donor was synthesized.
- Keith, D. Jamin,Townsend, Steven D.
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supporting information
p. 12939 - 12945
(2019/08/22)
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- Glycerol acetal(ketal) ether and synthesis method thereof
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The invention discloses glycerol acetal(ketal) ether and a synthesis method thereof, and relates to the technical field of chemical industry synthesis. According to the method, two functional groups acetal(ketal) and ether are integrated into one molecule by using glycerol as a raw material, wherein the glycerol acetal(ketal) ether can improve the use efficiency of unit fuel additives; the method comprises two synthesis routes, etherification and acetalization (ketalization) can be sequentially performed, or acetalization (ketalization) and etherification can be sequentially performed, wherein the etherification reaction is an atomic economic reaction; the by-product of the acetalization (ketalization) reaction is only one molecule of water, such that the method is environmentally friendly and efficient; the yield of the glycerol acetal(ketal) ether is high, and can be up to 99%; and the solid acid catalyst is used, is clean and efficient, and can be recycled so as to greatly reduce the cost and achieve the high industrial value.
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Paragraph 0075; 0079
(2019/10/04)
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Amorphous SiO2-SO3H [1] with a small surface area and 1.32-mmol H+/g was used for the one-step preparation of solketal from glycerol and acetone; a 20%-w/w catalyst mixture (10% [1] and 10% (Bu4N)(BF4) was found to be very efficient for the synthesis of disolketal ether and of oxygenated biofuels fatty acids solketal esters (FASEs), by direct esterification of the caprylic, lauric, stearic, oleic and linoleic acids with solketal in a 4:1 acid:solketal ratio in refluxing toluene. Solketal acetate was also produced in quantitative yields.
- Barbosa, Sandro L.,Lima, Pamela C.,dos Santos, Wallans T.P.,Klein, Stanlei I.,Clososki, Giuliano C.,Caires, Franco J.
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- Method for preparing solketal by recovering crude glycerol
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The invention provides a method for preparing solketal by recovering crude glycerol, and relates to the technical field of chemical methods for preparing solketal by using crude glycerol. The method comprises: carrying out acid washing on crush glycerol by using an acid to achieve weak acidity, filtering, separating the crude glycerol, pouring the treated crude glycerol into a reaction kettle, adding acetone, adding concentrated sulfuric acid, adding a drying agent, removing the water by an imitated Soxhlet extractor, refluxing until completing the reaction, cooling to achieve a temperature of50 DEG C, adding an alkali, neutralizing, adjusting the pH value to 6.5, filtering to obtain a filtrate, distilling to recover acetone, and carrying out pressure reducing distillation to obtain the solketal, wherein the purity of the product can achieve 99%.
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Paragraph 0007-0009
(2019/01/15)
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- COALESCING AGENT DERIVED FROM DIOXOLANE DERIVATIVES
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The present invention relates to a coalescing agent as represented in structure (I); wherein; n is integer from 1 to 8; R1 and R2 independently represent group selected from hydrogen atom, alkyl, alkenyl, alkynyl, phenyl, benzyl groups, or optionally cyclic hydrocarbon containing heteroatom; and Y represents group selected from alkyl, alkenyl, alkynyl, phenyl, benzyl groups, or cyclic hydrocarbon containing heteroatom. The said coalescing agent can be used in coating application with efficacy to provide smooth consistent film with chemical and scratch resistant and has no pungent odour, wherein the preparation method of this compound is simplify and employs less harmful chemicals.
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Paragraph 0069-0070
(2019/07/10)
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- Method for synthesizing acetone ketal glycerinum acetate from glycerinum
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The invention discloses a method for synthesizing acetone ketal glycerinum acetate from glycerinum. The method comprises the following steps: firstly, putting acetone and a biodiesel byproduct, namelyglycerinum, into a condensation kettle, performing a condensation reaction in the presence of a catalyst A, and performing extraction and distillation after the reaction so as to obtain acetone ketalglycerinum; putting the acetone ketal glycerinum into a reaction/azeotropic distillation device, performing an ester exchange reaction with acetate in the presence of a catalyst B, and performing aftertreatment, so as to obtain a target product, namely the acetone ketal glycerinum acetate. Through condensation and ester exchange reactions, the biodiesel byproduct, namely the glycerinum, is converted into the acetone ketal glycerinum acetate which can be used as a fuel additive, separation is simple, the yield is high, the preparation process is simple, the catalyst is small in equipment corrosion, environment pollution caused by glycerinum wastes can be avoided, the environment can be protected, meanwhile, additional values of products can be increased, and development of the biodiesel industry can be facilitated.
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Paragraph 0015; 0016; 0017; 0018; 0019
(2019/12/25)
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- HYDROPHILIC FLUORINATED MOLECULES FOR LIPOSOMAL 19F MRI PROBES WITH UNIQUE MR SIGNATURES
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Readily available hydrophilic and small organofluorine moieties were condensed via “click chemistry” to generate nonionic hydrophilic fluorinated molecules with unique 19F MR signatures. These were used to fabricate stable liposome formulations for imaging various tissue types. This approach was tailored to exploit the broad spectrum of organic 19F molecular species and to generate probes with distinct 19F MRI signatures for simultaneous assessment of multiple molecular targets within the same target volume.
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Paragraph 0101; 0102
(2018/06/15)
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- Monomyristin and monopalmitin derivatives: Synthesis and evaluation as potential antibacterial and antifungal agents
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In the present work, monoacylglycerol derivatives, i.e., 1-monomyristin, 2-monomyristin, and 2-monopalmitin were successfully prepared from commercially available myristic acid and palmitic acid. The 1-monomyristin compound was prepared through a transesterification reaction between ethyl myristate and 1,2-O-isopropylidene glycerol, which was obtained from the protection of glycerol with acetone, then followed by deprotection using Amberlyst-15. On the other hand, 2-monoacylglycerol derivatives were prepared through enzymatic hydrolysis of triglycerides in the presence of Thermomyces lanuginosa lipase enzymes. The synthesized products were analyzed using fourier transform infrared (FTIR) spectrophotometer, gas or liquid chromatography-mass spectrometer (GC-MS or LC-MS), and proton and carbon nuclear magnetic resonance (1H- and13C-NMR) spectrometers. It was found that monomyristin showed high antibacterial and antifungal activities, while 2-monopalmitin did not show any activity at all. The 1-monomyristin compound showed higher antibacterial activity against Staphylococcus aureus and Aggregatibacter actinomycetemcomitans and also higher antifungal activity against Candida albicans compared to the positive control. Meanwhile, 2-monomyristin showed high antibacterial activity against Escherichia coli. The effect of the acyl position and carbon chains towards antibacterial and antifungal activities was discussed.
- Jumina,Nurmala, Asma,Fitria, Anggit,Pranowo, Deni,Sholikhah, Eti Nurwening,Kurniawan, Yehezkiel Steven,Kuswandi, Bambang
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- Utilization of hexabromoacetone for protection of alcohols and aldehydes and deprotection of acetals, ketals, and oximes under UV irradiation
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Hexabromoacetone (HBA) was efficiently used for the protection of alcohols and aldehydes and deprotection of benzaldehyde dimethyl acetal, solketal, and other acetals and ketals. In only 10?min, the protection of glycerol yielded 90% of solketal and protection of benzaldehyde gave 95% of benzaldehyde dimethyl acetal. The deprotection of benzaldehyde dimethyl acetal under UV irradiation gave over 90% yield of benzaldehyde within 15?s using only 2.5?mol% of HBA. HBA was also successfully used for deoximation. Solvent was found to play an important role in the efficiency of HBA for these reactions.
- Chaiseeda, Kittichai,Chantharadet, Ladawan,Chavasiri, Warinthorn
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p. 1305 - 1323
(2017/10/30)
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- ANTIBACTERIAL COMPOSITION INCLUDING BENZOIC ACID ESTER AND METHODS OF INHIBITING BACTERIAL GROWTH UTILIZING THE SAME
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Antibacterial compositions and methods for inhibiting bacterial growth are disclosed. The antibacterial compositions can include a carrier and an antibacterial agent including a benzoic acid ester. The benzoic acid ester can have a carbon chain having a length of two to ten. The benzoic acid ester can have a hydroxyl group on the carbon chain.
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Page/Page column 22-23
(2018/08/26)
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- Solketal formation from glycerol and acetone over hierarchical zeolites of different structure as catalysts
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Glycerol acetalization reaction with acetone was performed at 343?K and using a 1:1 molar ratio of glycerol to acetone in the feed over hierarchical zeolites comprising pores of different diameters (MFI, BEA, and MOR). The best catalytic performance for glycerol acetalization was exhibited by hierarchical (micro-mesoporous) MFI zeolites. Glycerol conversion over MFI zeolites exceeded 80%, with almost 100% selectivity to the desired product (4-hydroxymethyl-2,2-dimethyl-1,3-dioxolane known as solketal). A significant increase in glycerol conversion and also selectivity to solketal in the studied reaction resulted from the easier accessibility of the active sites to reagents due to the formation of mesopores by means of desilication of the microporous zeolites.
- Kowalska-Kus,Held,Frankowski,Nowinska
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p. 205 - 212
(2016/12/07)
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- Isostructural metal-carboxylates MIL-100(M) and MIL-53(M) (M: V, Al, Fe and Cr) as catalysts for condensation of glycerol with acetone
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The synthesis of solketal from acetone and glycerol (I) was investigated in the presence of the isostructural MOFs of the families MIL-100(M) and MIL-53(M) (M = V, Al, Fe and Cr) and mixed MIL-53(Al,V) (Al/V – 100/0, 75/25, 50/50, 25/75 and 0/100 atom/atom). The main products were a five-membered solketal (2,2-dimethyl-1,3-dioxane-4-methanol, (II)) and a six-membered acetal (2,2-dimethyl-dioxane-5-ol, (III)). It was demonstrated that the reaction rate and isomer selectivity depend on different parameters such as the type of metal ion, the length of the M-O bond, the rate constant for the exchange of the water molecules from the first coordination sphere of a metal ion and the value of the zero point of the surface charge (pHPZC). Investigation of mixed MIL-53(Al,V) shows that the reaction rate and selectivity towards (II) increase with increasing V3+ content in MIL-53(Al,V). V-containing MOFs possess a high activity and selectivity at 25 °C. The efficiencies of MIL-100(V) and MIL-47(V) were higher than those of H2SO4, SnCl2 and p-toluenesulfonic acid at 25 °C. The MIL-100(V) catalyst showed good reusability for 4 catalyst recycles.
- Timofeeva, Maria N.,Panchenko, Valentina N.,Khan, Nazmul Abedin,Hasan, Zubair,Prosvirin, Igor P.,Tsybulya, Sergey V.,Jhung, Sung Hwa
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p. 167 - 174
(2016/11/23)
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- [...] derivatives
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PROBLEM TO BE SOLVED: To provide a dibenzyl trithiocarbonate derivative having various functional groups at both terminals of the molecule and to provide a method for producing the same.SOLUTION: There is provided a dibenzyl trithiocarbonate derivative represented by the following general formula (1): wherein, Ar is a phenylene group or a naphthylene group; R is an acetoxy group, a hydroxy group, a hydroxymethyl group, or a methoxycarbonyl group having a substituent represented by the formula, -C(O)-O-CH-R(wherein, Ris a Cto Calkyl or a Cto Calkenyl group having a substituent). There is provided a method for producing a dibenzyl trithiocarbonate derivative represented by the general formula (1) in which a compound represented by the formula (3) (wherein X is a halogen atom) is reacted with a trithiocarbonate in an amide-based solvent to trithiocarbonate.
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Paragraph 0061; 0062
(2018/01/02)
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- A bifunctional cerium phosphate catalyst for chemoselective acetalization
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Acid-base solid catalysts synthesized with structurally controlled uniform active sites can lead to unique catalysis. In this study, a CePO4 catalyst was synthesized using a hydrothermal method and found to exhibit high catalytic performance for the chemoselective acetalization of 5-hydroxymethylfurfural with alcohols, in sharp contrast to other homogeneous and heterogeneous acid and/or base catalysts. In the presence of CePO4, various combinations of carbonyl compounds and alcohols are efficiently converted into the corresponding acetal derivatives in good to excellent yields. Mechanistic studies show that CePO4 most likely acts as a bifunctional catalyst through the interaction of uniform Lewis acid and weak base sites with 5-hydroxymethylfurfural and alcohol molecules, respectively, which results in high catalytic performance.
- Kanai, Shunsuke,Nagahara, Ippei,Kita, Yusuke,Kamata, Keigo,Hara, Michikazu
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p. 3146 - 3153
(2017/04/04)
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- Synthesis of novel 1,2-diol containing azo dyes for polymeric substrates
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Two novel 1,2-diol containing azo dyes have been synthesized for application on polymeric textile substrates. We used multistep synthesis scheme which involved selectively bonding azo chromophore with glycerol moiety such that only one alcohol out of the three gets bonded to the chromophore while rest two remain unchanged. The 1,2-diol moiety, common in both dyes, is responsible for forming hydrogen bonds with polar sites on a polymeric substrate. The molecular structure of the final molecule and synthesized intermediates were elucidated by UV/Vis, FT-IR, MS (EI, ESI, and CI) and 1H-NMR spectroscopic techniques. Dyes were applied to polyester and nylon 66 fabrics as disperse dyes by exhaust dyeing method and furnished good to excellent fastness properties on both of them.
- Sheikh, Hamdullah Khadim,Kazmi, Mehdi Hassan
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p. 3496 - 3500
(2017/08/14)
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- Synthesis of novel glycerol-derived 1,2,3-triazoles and evaluation of their fungicide, phytotoxic and cytotoxic activities
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The synthesis of a series of 1,2,3-triazoles using glycerol as starting material is described. The key step in the preparation of these triazolic derivatives is the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), also known as click reaction, between 4-(azidomethyl)-2,2-dimethyl-1,3- dioxolane (3) and different terminal alkynes. The eight prepared derivatives were evaluated with regard to their fungicide, phytotoxic and cytotoxic activities. The fungicidal activity was assessed in vitro against Colletotrichum gloeosporioides, the causative agent of papaya anthracnose. It was found that the compounds 1-(1-((2,2-dimethyl-1,3-dioxolan-4-yl)methyl)-1H-1,2,3-triazol-4-yl)- cyclo-hexanol (4g) and 2-(1-((2,2-dimethyl-1,3-dioxolan-4-yl)methyl)-1H-1,2,3-triazol-4-yl)propan-2-ol (4h) demonstrated high efficiency in controlling C. gloeosporioides when compared to the commercial fungicide tebuconazole. The triazoles did not present any phytotoxic effect when evaluated against Lactuca sativa. However, five derivatives were mitodepressive, inducing cell death detected by the presence of condensed nuclei and acted as aneugenic agents in the cell cycle of L. sativa. It is believed that glycerol derivatives bearing 1,2,3-triazole functionalities may represent a promising scaffold to be explored for the development of new agents to control C. gloeosporioides.
- Costa, Adilson Vidal,De Oliveira, Marcos Vinicius Lacerda,Pinto, Roberta Trist?o,Moreira, Luiza Carvalheira,Gomes, Ediellen Mayara Corrêa,De Assis Alves, Thammyres,Pinheiro, Patrícia Fontes,De Queiroz, Vagner Tebaldi,Vieira, Larissa Fonseca Andrade,Teixeira, Robson Ricardo,De Jesus, Waldir Cintra
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