- A study on the cataluminescence of propylene oxide on FeNi layered double hydroxides/graphene oxide
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In this work, FeNi layered double hydroxides/graphene oxide (FeNi LDH/GO) was prepared, which exhibits excellent selective cataluminescent performance towards propylene oxide. The selectivity and sensitivity of the cataluminescence (CTL) reaction were investigated in detail. Moreover, the catalytic reaction mechanism, including the intermediate products and the conversion of reactants to products, was discussed based on both the experimental and computational results. Furthermore, the proposed FeNi LDH/GO based CTL sensor was successfully applied for the determination of propylene oxide residue in fumigated raisins, which indicates extensive application potential for rapid food safety evaluation.
- Li, Ming,Hu, Yufei,Li, Gongke
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p. 11823 - 11830
(2021/07/11)
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- Bio-based solvents and gasoline components from renewable 2,3-butanediol and 1,2-propanediol: Synthesis and characterization
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In this study approaches for chemical conversions of the renewable compounds 1,2-propanediol (1,2-PD) and 2,3-butanediol (2,3-BD) that yield the corresponding cyclic ketals and glycol ethers have been investigated experimentally. The characterization of the obtained products as potential green solvents and gasoline components is discussed. Cyclic ketals have been obtained by the direct reaction of the diols with lower aliphatic ketones (1,2-PD + acetone→ 2,2,4-trimethyl-1,3-dioxolane (TMD) and 2,3-BD + butanone-2→2-ethyl-2,4,5-trimethyl-1,3-dioxolane (ETMD)), for which the ΔH0 r, ΔS0 r and ΔG0 r values have been estimated experimentally. The monoethers of diols could be obtained through either hydrogenolysis of the pure ketals or from the ketone and the diol via reductive alkylation. In the both reactions, the cyclic ketals (TMD and ETMD) have been hydrogenated in nearly quantitative yields to the corresponding isopropoxypropanols (IPP) and 3-sec-butoxy-2-butanol (SBB) under mild conditions (T = 120-140 °C, p(H2) = 40 bar) with high selectivity (>93%). Four products (TMD, ETMD, IPP and SBB) have been characterized as far as their physical properties are concerned (density, melting/boiling points, viscosity, calorific value, evaporation rate, Antoine equation coe°Cients), as well as their solvent ones (Kamlet-Taft solvatochromic parameters, miscibility, and polymer solubilization). In the investigation of gasoline blending properties, TMD, ETMD, IPP and SBB have shown remarkable antiknock performance with blending antiknock indices of 95.2, 92.7, 99.2 and 99.7 points, respectively.
- Bermeshev, Maxim,Goncharova, Arina,Kniazeva, Mariia,Kosyakov, Dmitry,Ladesov, Anton,Maximov, Anton,Ni, Denis,Samoilov, Vadim,Zarezin, Danil
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- 8-Hydroxy-2-methylquinoline-modified H4SiW12O40: A reusable heterogeneous catalyst for acetal/ketal formation
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A heteropoly acid based organic hybrid heterogeneous catalyst, HMQ-STW, was prepared by combining 8-hydroxy-2-methylquinoline (HMQ) with Keggin-structured H4SiW12O40 (STW). The catalyst was characterized via elemental analysis, X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TG) and potentiometric titration analysis. The catalytic performance of the catalyst was assessed in the ketalization of ketones with glycol or 1,2-propylene glycol. Various reaction parameters, such as the glycol to cyclohexanone molar ratio, catalyst dosage, reaction temperature and time, were systematically examined. HMQ-STW exhibited a relatively high yield of corresponding ketal, with 100% selectivity under the optimized reaction conditions. Moreover, catalytic recycling tests demonstrated that the heterogeneous catalyst exhibited high potential for reusability, and it was revealed that the organic modifier HMQ plays an important role in the formation of a heterogeneous system and the improvement of structural stability. These results indicated that the HMQ-STW catalyst is a promising new type of heterogeneous acid catalyst for the ketalization of ketones.
- Liu, Li-Jun,Luan, Qing-Jie,Lu, Jing,Lv, Dong-Mei,Duan, Wen-Zeng,Wang, Xu,Gong, Shu-Wen
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p. 26180 - 26187
(2018/08/04)
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- A 2, 2 - dimethoxy propane preparation method (by machine translation)
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The invention discloses 2, 2 - dimethoxy propane synthesis in the technical field of a 2, 2 - dimethoxy propane preparation method, this invention adopts the indirect method for the preparation of 2, 2 - dimethoxy propane, step (1) the propylene glycol and acetone reaction, to produce 2, 2, 4 - trimethyl - 1, 3 dioxolane, in order to water-free ferric sulfate as a catalyst, not only high catalytic efficiency, and insoluble in the reaction system, as compared with the other soluble strong catalyst, its reaction is apt to separation, the reaction operation is simplified, and can be recycled, petroleum ether as a sub-agent, through the return water diversion, the water generated by the reaction out of the system the outer, right to in order to facilitate the reaction, the reaction is more fully, at the same time shorten the reaction time, step (2) adopting the step (1) product 2, 2, 4 - trimethyl - 1, 3 dioxolane and methanol reaction, the preparation of 2, 2 - dimethoxy propane, in order to water-free three-aluminum chloride as the catalyst, catalytic effect, and finally to the preparations 2, 2 - dimethoxy propane and higher yield at the same time the preparation time is short. (by machine translation)
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Paragraph 0014-0016; 0017; 0018; 0020; 0021
(2019/01/08)
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- FUEL COMPOSITIONS COMPRISING HYDROPHOBIC DERIVATIVES OF GLYCERINE
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The object of the present invention relates to a composition that can be used as fuel comprising: at least one hydrocarbon mixture at least one hydrophobic ketal or acetal of glycerine. Said composition can be advantageously used as fuel for diesel or gasoline engines.
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Page/Page column 21
(2013/10/22)
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- Catalytic hydrogenation of esters. Development of an efficient catalyst and processes for synthesising (R)-1,2-propanediol and 2-(l-Menthoxy)ethanol
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A ruthenium catalyst for the reduction of esters by hydrogenation has been developed. Processes for the hydrogenation of esters have also been developed for (R)-1,2-propanediol and 2-(l-menthoxy)ethanol. The catalyst shows good catalytic activity for the hydrogenation of esters in methanol. Methyl lactate was reduced at 30 °C and gave turnover numbers (TON) up to 4000. The optical purity of the (R)-1,2-propanediol made by the hydrogenation of methyl (R)-lactate was higher than that via the asymmetric hydrogenation of hydroxyacetone. A hydrogenation process to replace the lithium aluminum hydride (LAH) reduction used in the production of 2-(l-menthoxy)ethanol was developed.
- Kuriyama, Wataru,Matsumoto, Takaji,Ogata, Osamu,Ino, Yasunori,Aoki, Kunimori,Tanaka, Shigeru,Ishida, Kenya,Kobayashi, Tohru,Sayo, Noboru,Saito, Takao
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experimental part
p. 166 - 171
(2012/05/20)
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- Liquid-phase dehydration of propylene glycol using solid-acid catalysts
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In this work we combine experiments with Density Functional Theory (DFT) calculations to investigate the heterogeneous dehydration of propylene glycol. The reactions were carried out with pure, liquid propylene glycol over MFI-framework zeolite catalysts or the mesoporous sulfonic-acid resin Amberlyst 36Dry. When Amberlyst 36Dry was used, propylene glycol dehydrated to form propionaldehyde with 77% selectivity. All of the propionaldehyde further reacted with propylene glycol to form a cyclic acetal. The final products consisted of 78% acetal, 13% dipropylene glycol, and the remaining 9% was composed of acetone and a cyclic ketal formed from acetone. The zeolite catalysts demonstrated significantly higher selectivity toward dipropylene glycol compared to Amberlyst 36Dry. Furthermore, the zeolite had a lower conversion to cyclic acetals, improving the selectivity toward C3 products, acetone and propionaldehyde. DFT calculations confirmed that propionaldehyde is the favorable product in both catalysts, since it can be formed either through dehydration of the secondary hydroxyl group or via dehydration of the primary hydroxyl group with a concerted pinacol rearrangement. However, in the case of zeolites, the cyclic acetals experience steric hindrance since their size is comparable to that of the zeolite pores. Thus we argue that the cyclic acetals produced over the zeolite catalyst were formed homogeneously from the C3 products which diffused out of the zeolite pores.
- Courtney, Timothy D.,Nikolakis, Vladimiros,Mpourmpakis, Giannis,Chen, Jingguang G.,Vlachos, Dionisios G.
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- Catalytic hydrogenation of cyclic carbonates: A practical approach from CO2 and epoxides to methanol and diols
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As an economical, safe and renewable carbon resource, CO2 turns out to be an attractive C1 building block for making organic chemicals, materials, and carbohydrates.[1] From the viewpoint of synthetic chemistry,[2] the utilization of CO2 as a feedstock for the production of industrial products may be an option for the recycling of carbon.[3] On the other hand, the transformation of chemically stable CO2 represents a grand challenge in exploring new concepts and opportunities for the academic and industrial development of catalytic processes.[4] The catalytic hydrogenation of CO2 to produce liquid fuels such as formic acid (HCO 2H)[5] or methanol[6] is a promising solution to emerging global energy problems. Methanol, in particular, is not only one of the most versatile and popular chemical commodities in the world, with an estimated global demand of around 48 million metric tons in 2010, but is also considered as the key to weaning the world off oil in the future.[6e, f] Although the production of methanol has already been industrialized by the hydrogenation of CO with a copper/zinc-based heterogeneous catalyst at high temperatures (250-300°C) and high pressures (50-100 atm),[6e, 7] the development of a practical catalytic system for the hydrogenation of CO2 into methanol still remains a challenge, as high activation energy barriers have to be overcome for the cleavage of the C=O bonds of CO2, albeit with favorable thermodynamics.[8] Heterogeneous catalysis for the hydrogenation of CO 2 into CH3OH has been extensively investigated, and Cu/Zn-based multi-component catalyst was found to be highly selective with a long life, but under relatively harsh reaction conditions (250 °C, 50 atm).[3b, 6d] Therefore, the production of methanol from CO2 by direct hydrogenation under mild conditions is still a great challenge for both academia and industry.
- Han, Zhaobin,Rong, Liangce,Wu, Jiang,Zhang, Lei,Wang, Zheng,Ding, Kuiling
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supporting information
p. 13041 - 13045
(2013/03/13)
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- Synthesis of 1,3-dioxolanes by the addition of ketones to epoxides by using [Cp*Ir(NCMe)3]2+ as catalyst
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A series of 1,3-dioxolanes have been prepared by the addition of ketones to epoxides in the presence of the catalyst [Cp*Ir(NCMe)3]2+, Cp=C5Me5. The reactions proceed readily at 22°C and the yields are good. The following 1,3-dioxolanes: 2,2,4-trimethyl-1,3-dioxolane, 1; 2,2-dimethyl-4-vinyl-1,3-dioxolane, 2; 2,2-dimethyl-4-phenyl-1,3-dioxolane, 3; 2,2-diethyl-4-methyl-1,3-dioxolane, 4; 2,2-diethyl-4-vinyl-1,3-dioxolane, 5; 2,2-diethyl-4-phenyl-1,3-dioxolane, 6 were prepared from the appropriate epoxide and carbonyl compounds. An inversion of configuration at the carbon atom at the C-O bond cleavage site of the epoxide was observed to occur in the formation of the dioxolanes: R, S,- 2,2,4,5-tetramethyl-1,3-dioxolane, 7 and a mixture of R,R- and S,S-2,2,4,5-tetramethyl-1,3-dioxolane, 8 obtained from the reactions of acetone with R, R,-/S, S,-buten-2-oxide and R, S,-buten-2-oxide, respectively.
- Adams, Richard D.,Barnard, Thomas S.,Brosius, Kellie
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p. 358 - 361
(2007/10/03)
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- Transformation of 1,2-diols over perfluorinated resinsulfonic acids (Nafion-H)
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The transformations of 1,2-diols over perfluorinated resinsulfonic acids (Nafion-H) were studied, and correlations were examined between the structures of the investigated diols, the possible dehydration routes and the catalytic properties of Nafion-H. Comparisons were also made between the catalytic properties of Nafion-H and NaHX zeolite. Because of its stronger acidity, Nafion-H functions at temperatures considerably lower than those for the usual dehydrating catalysts, e.g. the zeolites. As is well established for other solid electrophilic catalysts, the dehydration of 1,2-diols mainly proceeds via the pinacol rearrangement. The lower temperatures and the stronger acidity of Nafion-H strongly favour the pinacol rearrangement versus 1,2-elimination. The reaction conditions are also advantageous for the formation of substituted 1,3-dioxolanes in a secondary condensation step between the unreacted diol and the primarily formed carbonyl compounds. Nafion-H gradually deactivates during long use, but it can be partially reactivated by washing with acetone.
- Bucsi,Bucsi, Imre,Molnar,Molnar, Arpad,Bartok,Bartok, Mihaly,Olah,Olah, George A.
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p. 8195 - 8202
(2007/10/02)
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- Transacetalation: a convenient, nonaqueous method for effecting the deprotection of isopropylidene and benzylidene derivatives of sugars
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Sugar isopropylidene and benzylidene derivatives can be readily deprotected under nonaqueous conditions by treatment of a dichloromethane solution of the protected sugar with an excess of a sacrificial glycol in the presence of a catalytic amount of p-toluenesulfonic acid.The reaction is conveniently monitored by GLC, and the fully or partially deprotected product precipitates from solution.
- Andrews, Mark A.,Gould, George L.
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p. 141 - 148
(2007/10/02)
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- N-Benzyl Pyridinium Salta as New Useful Catalysts for Transformation of Epoxides to Cyclic Acetals, Orthoesters, and Orthocarbonates
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In the presence of catalytic amount of N-(4-methoxybenzyl)-2-cyanopyridinium hexafluoroantimonate, the reaction of a few epoxides with aldehydes, ketones, lactones, and carbonates efficiently afforded corresponding cyclic acetals, orthoesters, and orthocarbonates under mild conditions.
- Lee, Sang-Bong,Takata, Toshikazu,Endo, Takeshi
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p. 2019 - 2022
(2007/10/02)
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- Synthese d'acetals cycliques dans des conditions douces; Applications a l'acetalisation du chloramphenicol
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Acetalization of 1-2 and 1-3 diols, even as sterically crowded as chloramphenicol, by carbonyl derivatives with substituents of various sizes has been performed at room temperature under mild conditions, by using heterogeneous catalysis (sulfonated polystyrene) in the presence of molecular sieves.Several new acetals of chloramphenicol have thus been obtained in good yields, isolated and characterized.
- Meslard, J. C.,Subira, F.,Vairon, J. P.,Guy, A.,Garreau, R.
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- ANALYTICAL ENANTIOMER SEPARATION OF ALIPHATIC DIOLS AS BORONATES AND ACETALS BY COMPLEXATION GAS CHROMATOGRAPHY
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Cyclic boronates and acetals of mono- and dialkylsubstituted 1,2-, 2,3- 1,3-and 1,4-diols have been quantitatively separated into enantiomers by complexation gas chromatography utilizing optically active metal chelates.An efficient, precise and sensitive method for determining enantiomeric purities for volatile glycols is thus available.
- Schurig, V.,Wistuba, D.
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p. 5633 - 5636
(2007/10/02)
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- Heterobicycles sulfures derives de l'α-thioglycerol. Synthese d'alkyl-2,8-dioxa-6-thiabicyclooctanes
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The synthesis of 2,8-dioxa-6-thiabicyclooctanes, substituted by alkyl or phenyl groups in positions 1, 4, or 7, is described.Four synthetic routes are compared: (i) action of sodium sulfide on 2,4-dichloro-1,3-dialkyldioxolanes; (ii) action of sodium sulfide on the ditosylates of 2,4-dihydroxyalkyl-1,3-dioxolanes; (iii) action of α-haloketones on α-thioglycerol; and (iv) action of α-hydroxyketones on α-thioglycerol.The structures of the dioxathiabicyclooctanes have been established by proton nmr (mass spectra have already been described) and chemically confirmed by desulfurization by Raney Nickel.
- Gelas, Jacques,Teppaz-Misson, Marc
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p. 1487 - 1493
(2007/10/02)
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- Enantiomeric Interactions and Reaction Rates: Ketalization of (S)- and (RS)-1,2-Propanediols
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Aliphatic ketones, e.g., butanone, are converted nearly quantitatively to the corresponding dioxolanes (ketals) in neat (S)- or (RS)-1,2-propanediol containing dichloroacetic acid.The reactions follow the pseudo-first-order law at a given acid concentration, are inhibited by water, and proceed approximately twofold faster in (RS)-diol-O,O-d2 than in undeuterated diol.No difference in rates greater than 1percent could be detected between (S)- and (RS)-diols at identical temperatures, acid concentrations, and water concentrations.Thus, for a chiral diol molecule and the activated complex, free-energy differences are virtually the same in (S)- and (RS)-diols as solvents.Differences in interactions among identical and enantiomeric molecules, if any, are evidently matched by differences in the activated complexes.
- Wynberg, Hans,Lorand, John P.
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p. 2538 - 2542
(2007/10/02)
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