623-36-9Relevant academic research and scientific papers
Accelerating Amine-Catalyzed Asymmetric Reactions by Intermolecular Cooperative Thiourea/Oxime Hydrogen-Bond Catalysis
Afewerki, Samson,Córdova, Armando,Ibrahem, Ismail,Ma, Guangning,Zhang, Kaiheng
supporting information, p. 3043 - 3049 (2021/07/22)
The ability of intermolecular cooperative thiourea/oxime hydrogen-bond catalysis for improving and accelerating asymmetric aminocatalysis is presented. The two readily available hydrogen-bond-donating catalysts operates in synergy with a chiral amine catalyst to accomplish highly stereoselective transformations. The synergistic catalyst systems simultaneously activate both electrophiles and nucleophiles, and make the transformations more chemo- and stereoselective. This was exemplified by performing co-catalytic enantioselective direct intermolecular α-alkylation reactions of aldehydes, direct aldol reactions, and asymmetric conjugate reactions, which gave the corresponding products in high yields and enantiomeric ratios.
Self-aldol condensation of aldehydes over Lewis acidic rare-earth cations stabilized by zeolites
Yan, Tingting,Yao, Sikai,Dai, Weili,Wu, Guangjun,Guan, Naijia,Li, Landong
, p. 595 - 605 (2020/09/01)
The self-aldol condensation of aldehydes was investigated with rare-earth cations stabilized by [Si]Beta zeolites in parallel with bulk rare-earth metal oxides. Good catalytic performance was achieved with all Lewis acidic rare-earth cations stabilized by
Heterogeneous catalytic condensation of propanal
Afaunov, A. A.,Bruk, L. G.,Flid, V. R.,Martsinkevich, E. M.
, p. 2031 - 2033 (2021/11/04)
The aldol homocondensation of propanal was studied in the presence of a heterogeneous titanium oxide catalyst modified with amino acid (AA) l-norleucine. The effects of the temperature and l-norleucine content on the conversion of propanal and selectivity of the process were studied. The reaction products were identified, and possible mechanisms are considered. A new catalyst (5% AA on titanium dioxide) was developed for the synthesis of 2-methyl-2-pentenal with the selectivity >90%.
SELF-CONDENSATION OF ALDEHYDES
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Paragraph 0021; 0027, (2020/06/05)
An efficient process useful for the self-condensation of aliphatic aldehydes is provided, catalyzed by dialkylammonium carboxylate salts. In particular, the invention provides a facile method for the preparation of 2-ethyl hexenal via the self-condensation of butyraldehyde using various dialkylammonium carboxylates, e.g., diisopropylammonium acetate or dimethylammonium acetate, as catalyst. Additionally, residual nitrogen arising from the catalyst can be reduced to -100 ppm levels in the product via a simple washing procedure. The invention provides a process for preparing alkenals under conditions which limit the formation of undesired impurities and high-boiling oligomeric substances.
Kinetic Treatments for Catalyst Activation and Deactivation Processes based on Variable Time Normalization Analysis
Martínez-Carrión, Alicia,Howlett, Michael G.,Alamillo-Ferrer, Carla,Clayton, Adam D.,Bourne, Richard A.,Codina, Anna,Vidal-Ferran, Anton,Adams, Ralph W.,Burés, Jordi
supporting information, p. 10189 - 10193 (2019/06/25)
Progress reaction profiles are affected by both catalyst activation and deactivation processes occurring alongside the main reaction. These processes complicate the kinetic analysis of reactions, often directing researchers toward incorrect conclusions. We report the application of two kinetic treatments, based on variable time normalization analysis, to reactions involving catalyst activation and deactivation processes. The first kinetic treatment allows the removal of induction periods or the effect of rate perturbations associated with catalyst deactivation from kinetic profiles when the quantity of active catalyst can be measured. The second treatment allows the estimation of the activation or deactivation profile of the catalyst when the order of the reactants for the main reaction is known. Both treatments facilitate kinetic analysis of reactions suffering catalyst activation or deactivation processes.
Organic compound as well as preparation method and application thereof
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Paragraph 0039; 0041; 0058; 0060, (2019/10/04)
The invention relates to an organic compound as well as a preparation method and application thereof. The organic compound has a structural formula I shown in the specification, in the formula, R4 is H; R1, R2 and R3 are alkyl or H of which the carbon number is an integer; the total carbon number of R1, R2, R3 and R4 is 0-3; R5 and R6 are of an identical structure and are both saturated alkyl with 1-3 carbon atoms; A is a polyoxy alkenyl ether group, a sulfation polyoxy alkenyl ether group, an aliphatic, alicyclic or aromatic group which forms an ester group with adjacent oxygen atoms, or an aliphatic, alicyclic or aromatic group which comprises other ester groups. Due to a carbon chain structure similar to Guerbet alcohol and an alcoholic hydroxyl derivative structure at a para-site in the organic compound, the organic compound has excellent low-temperature properties and good degradability in a surfactant, ester type lubricating oil or a plasticizer.
Method for preparing high-carbon branched-chain secondary alcohol
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Paragraph 0037; 0038, (2019/10/01)
The invention relates to a method for preparing high-carbon branched-chain secondary alcohol. The method comprises the steps: preparing branched-chain olefin aldehyde through self-condensation of linear aliphatic aldehyde or branched-chain aliphatic aldehyde without tertiary carbon, performing a gas-liquid heterogeneous condensation reaction on the branched-chain olefin aldehyde and aliphatic ketone without tertiary carbon under the catalysis action of organic base so as to prepare branched-chain dienone, and performing hydrogenation on the branched-chain dienone so as to prepare unsaturated or saturated branched-chain secondary alcohol. The method has wide sources of raw materials and low cost, and the product has a certain structure, and is particularly suitable for preparation of secondary alcohol polyoxyethylene ether and secondary alcohol polyoxyethylene ether derivatives which have narrow molecular weight distribution; and the alcoholic hydroxyl group of the product is secondary alcohol which has a branched-chain structure but no tertiary carbon, the low temperature performance is excellent, and the biodegradability is good.
Silica gel-mediated self-aldol reactions of highly volatile aldehydes under organic solvent-free conditions without reflux condenser
Tanemura, Kiyoshi
supporting information, p. 1924 - 1928 (2019/06/24)
Silica gel-mediated self-aldol reactions were catalyzed by piperidine to give the corresponding α,β-conjugated aldehydes in good yields. The aldol reactions of 4-nitro-, 4-trifluoromethyl-, and 4-chlorobenzaldehydes with acetone afforded the corresponding aldol products. Highly volatile aldehydes and acetone could be employed even without a reflux condenser for these reactions. Silica gel could be recycled five times without any significant decrease of the yields of the products.
A study of the oxidehydration of 1,2-propanediol to propanoic acid with bifunctional catalysts
Bandinelli, Claudia,Basile, Francesco,Cavani, Fabrizio,Concepcion, Patricia,De Maron, Jacopo,Dimitratos, Nikolaos,Lambiase, Barbara,Nieto, Jose Manuel Lopez,Tabanelli, Tommaso
, (2019/06/28)
The gas-phase oxidehydration (ODH) of 1,2-propanediol to propionic acid has been studied as an intermediate step in the multi-step transformation of bio-sourced glycerol into methylmethacrylate. The reaction involves the dehydration of 1,2-propanediol into propionaldehyde, which occurs in the presence of acid active sites, and a second step of oxidation of the aldehyde to the carboxylic acid. The two reactions were carried out using a cascade strategy and multifunctional catalysts, made of W-Nb-O, W-V-O and W-Mo-V-O hexagonal tungsten bronzes, the same systems which are also active and selective in the ODH of glycerol into acrylic acid. Despite the similarities of reactions involved, the ODH of 1,2-propanediol turned out to be less selective than glycerol ODH, with best yield to propanoic acid no higher than 13percent, mainly because of the parallel reaction of oxidative cleavage, occurring on the reactant itself, which led to the formation of C1-C2 compounds.
Catalytic Reactions of Homo- and Cross-Condensation of Ethanal and Propanal
Martsinkevich,Bruk,Dashko,Afaunov,Flid,Sedov
, p. 1032 - 1035 (2019/01/03)
Abstract: Processes of catalytic homocondensation of propanal and its cross-condensation with ethanal and methanal in the presence of aniline and amino acids have been studied. The dependence of the conversion of the reactants and selectivity of the homo/heterocondensation process on the catalyst nature and temperature has been revealed. It has been shown that the maximum acrolein selectivity is reached in the case of using benzoyl-substituted derivatives in water, with the proportion of the products of further condensation decreasing. The selectivity for the ethanal homocondensation product 2-butenal decreases simultaneously as a result of the formation of linear and branched oligomers of successive condensation.
