2916-31-6Relevant academic research and scientific papers
Study of the catalytic activity of aluminum, zirconium and cerium pillared clays in the synthesis of 2,2-dimethyl-1,3-dioxolane
Mnasri, Saida,Besbes, Neji,Frini-Srasra, Najoua,Srasra, Ezzeddine
, p. 437 - 443 (2012)
The purified Tunisian clay G and the commercialized American clay W were pillared with zirconium, aluminum and mixed pillars zirconium-aluminum, cerium-zirconium, cerium-aluminum, and cerium-zirconium-aluminum. These different clays were used in the synthesis of 2,2-dimethyl-1,3-dioxolane 3 by acetalyzation of acetone 2 with ethylene glycol 1 under autogenously pressure and without solvent. Results indicate that the yield of product 3 depends of the nature and the acidity of the clay used and the time of reaction.
Bismuth carboxylates with brucite- and fluorite-related structures: Synthesis structure and properties
Sushrutha,Natarajan, Srinivasan
, p. 1743 - 1751 (2013)
Three new compounds of bismuth, [C4N2H 10][Bi(C7H4NO4)(C7H 3NO4)]·H2O, I, [Bi(C5H 3N2O4) (C5H2N 2O4)], II, and [Bi(μ2-OH)(C 7H3NO4)], III, have been prepared by the reaction between bismuth nitrate and heterocyclic aromatic dicarboxylic acids, 2,6-pyridinedicarboxylic acid, 4,5-imidazoledicarboxylic acid, and 3,4-pyridinedicarboxylic acid, respectively, under hydrothermal conditions. The structures of all the compounds have linkages between Bi2O 2 and the corresponding dicarboxylate forming a simple molecular unit in I, a bilayer arrangement in II, and a three-dimensional extended structure in III. The topological arrangement of the nodal building units in the structures indicates that a brucite-related layer (II) and fluorite-related arrangement (III) can be realized in these structures. By utilizing the secondary interactions, one can correlate the structure of III to a Kagome-related one. The observation of such classical inorganic related structures in the bismuth carboxylates is noteworthy. Lewis acid catalytic studies on the formation of ketal suggest the possible participatory role of the lone pair of electrons. All the compounds are characterized employing elemental analysis, IR, UV-vis, and thermal studies.
Low-Temperature Fluorination of Aerosol Suspensions of Hydrocarbons Utilizing Elemental Fluorine
Adcock, James L.,Horita, Kiyoshi,Renk, Ehrengard B.
, p. 6937 - 6947 (1981)
This work describes a new concept in direct fluorination methodology and an apparatus designed to achieve conditions necessary for the rapid, continuous partial or complete fluorination of hydrocarbon molecules under controlled conditions of temperature and concentration.Results from the fluorination of neopentane are presented which indicate that although the degree of fluorination for a given set of conditions indicates a Gaussian distribution, investigation of specific isomers indicates significant deviations from statistical isomer distributions in fluorinated neopentanes.Photochemical assisted fluorinations of neopentane, 1,4-dioxane, cyclohexane, and 2,2-dimethyl-1,3-dioxolane are described which produce the perfluorinated analogues directly in good purity and in high yields.
Synthesis of Asphaltene-Based Strongly Acidic Sulfonated Cation Exchangers and Determination of Their Catalytic Properties in the 2,2-Dimethyl-1,3-Dioxolane Synthesis Reaction
Borisov, D. N.,Foss, L. E.,Musin, L. I.,Musin, R. Z.,Nagornova, O. A.,Salikhov, R. Z.,Shabalin, K. V.,Yakubov, M. R.
, p. 709 - 715 (2020)
Abstract: Results of a study of the reaction products of asphaltene sulfonation with sulfuric acid in various temperature and time ranges have been described. The maximum sulfur content in sulfonated cation exchangers at an asphaltene sulfonation temperature of 100 and 120°С and a reaction time of 2 h has been determined. The maximum static exchange capacity of 4.3 meq/g has been found for the products of sulfonation with a sulfuric acid–oleum mixture. The asphaltene-based strongly acidic sulfocationite has been tested in the 2,2-dimethyl-1,3-dioxolane synthesis reaction.
H2-Free Selective Dehydroxymethylation of Primary Alcohols over Palladium Nanoparticle Catalysts
Yamaguchi, Sho,Kondo, Hiroki,Uesugi, Kohei,Sakoda, Katsumasa,Jitsukawa, Koichiro,Mitsudome, Takato,Mizugaki, Tomoo
, p. 1135 - 1139 (2020/12/29)
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.
Crystallinity after decarboxylation of a metal-carboxylate framework: indestructible porosity for catalysis
Cheng, Shengxian,Feng, Weijin,Gao, Wenpei,He, Jun,Hu, Jieying,Pan, Xiaoqing,Tieu, Peter,Xu, Zhengtao
, p. 11902 - 11910 (2020/09/21)
We report a curious case study of a Zr(iv)-carboxylate framework, which retains significant crystalline order after cascade thermocyclization of its linker components, and - more notably - after the crucial carboxylate links were severed by heat. Vigorous heat treatment (e.g., 450 °C and above) benzannulates the multiple alkyne groups on the linker to generate linked nanographene blocks and to afford real stability. The resultant Zr oxide/nanographene hybrid solid is stable in saturated NaOH and concentrated H3PO4, allowing a convenient anchoring of H3PO4into its porous matrix to enable size-selective heterogeneous acid catalysis. The Zr oxide components can also be removed by strong hydrofluoric acid to further enhance the surface area (up to 650 m2g?1), without collapsing the nanographene scaffold. The crystallinity order and the extensive thermal transformations were characterized by X-ray diffraction, scanning transmission electron microscopy (STEM), IR, solid state NMR and other instrumental methods.
Solvent-free ketalization of polyols over germanosilicate zeolites: The role of the nature and strength of acid sites
Podolean, Iunia,Zhang, Jin,Shamzhy, Mariya,Parvulescu, Vasile I.,?ejka, Ji?í
, p. 8254 - 8264 (2020/12/30)
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.
PROCESSES FOR FORMING GLYCOLS
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Paragraph 0095, (2020/05/28)
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.
Acid properties of organosiliceous hybrid materials based on pendant (fluoro)aryl-sulfonic groups through a spectroscopic study with probe molecules
Erigoni, Andrea,Paul, Geo,Meazza, Marta,Hernández-Soto, María Consuelo,Miletto, Ivana,Rios, Ramon,Segarra, Candela,Marchese, Leonardo,Raja, Robert,Rey, Fernando,Gianotti, Enrica,Díaz, Urbano
, p. 6308 - 6317 (2019/11/20)
Two different heterogeneous catalysts carrying aryl-sulfonic moieties, in which the aromatic ring was either fluorinated or not, were successfully synthesized. The multi-step synthetic approaches implemented involved the synthesis of the silyl-derivative, template-free one-pot co-condensation (at low temperature and neutral pH) and tethering reaction. A multi-technique approach was implemented to characterize the hybrid organic-inorganic catalysts involving TGA, N2 physisorption analysis, FTIR spectroscopy, and ss MAS NMR (1H, 13C, 29Si) spectroscopy. Specifically, the acidity of the organosiliceous hybrid materials was studied through the adsorption of probe molecules (i.e. CO at 77 K and NH3 and TMPO at room temperature) and a combination of FTIR and ss MAS NMR spectroscopy. The catalytic activity of the two hybrids was tested in the acetal formation reaction between benzaldehyde and ethylene glycol. Preliminary results indicated superior performances for the fluoro-aryl-sulfonic acid, compared to the non-fluorinated sample. The findings hereby reported open new avenues for the design of heterogeneous sulfonic acids with superior reactivity in acid-catalyzed reactions. Moreover, through the implementation of spectroscopic studies, using probe molecules, it was possible to investigate in detail the acidic properties of hybrid organosiliceous materials.
Utilization of 1,3-Dioxolanes in the Synthesis of α-branched Alkyl and Aryl 9-[2-(Phosphonomethoxy)Ethyl]Purines and Study of the Influence of α-branched Substitution for Potential Biological Activity
Pomeisl, Karel,Pohl, Radek,Snoeck, Robert,Andrei, Graciela,Kre?merová, Marcela
, p. 119 - 156 (2019/01/04)
Syntheses of α-branched alkyl and aryl substituted 9-[2-(phosphonomethoxy)ethyl]purines from substituted 1,3-dioxolanes have been developed. Key synthetic precursors, α-substituted dialkyl [(2-hydroxyethoxy)methyl]phosphonates were prepared via Lewis acid mediated cleavage of 1,3-dioxolanes followed by reaction with dialkyl or trialkyl phosphites. The best preparative yields were achieved under conditions utilizing tin tetrachloride as Lewis acid and triisopropyl phosphite. Attachment of purine bases to dialkyl [(2-hydroxyethoxy)methyl]phosphonates was performed by Mitsunobu reaction. Final α-branched 9-[2-(phosphonomethoxy)ethyl]purines were tested for antiviral, cytostatic and antiparasitic activity, the latter one determined as inhibitory activity towards Plasmodium falciparum enzyme hypoxanthine-guanine-xanthine phosphoribosyltransfesase. In most cases biological activity was only marginal.
