17609-31-3Relevant articles and documents
Synthesis of α,β- and β-Unsaturated Acids and Hydroxy Acids by Tandem Oxidation, Epoxidation, and Hydrolysis/Hydrogenation of Bioethanol Derivatives
Faria, Jimmy,Komarneni, Mallik R.,Li, Gengnan,Pham, Tu,Resasco, Daniel E.,Ruiz, Maria P.,Santhanaraj, Daniel
supporting information, p. 7456 - 7460 (2020/03/23)
We report a reaction platform for the synthesis of three different high-value specialty chemical building blocks starting from bio-ethanol, which might have an important impact in the implementation of biorefineries. First, oxidative dehydrogenation of ethanol to acetaldehyde generates an aldehyde-containing stream active for the production of C4 aldehydes via base-catalyzed aldol-condensation. Then, the resulting C4 adduct is selectively converted into crotonic acid via catalytic aerobic oxidation (62 % yield). Using a sequential epoxidation and hydrogenation of crotonic acid leads to 29 % yield of β-hydroxy acid (3-hydroxybutanoic acid). By controlling the pH of the reaction media, it is possible to hydrolyze the oxirane moiety leading to 21 % yield of α,β-dihydroxy acid (2,3-dihydroxybutanoic acid). Crotonic acid, 3-hydroxybutanoic acid, and 2,3-dihydroxybutanoic acid are archetypal specialty chemicals used in the synthesis of polyvinyl-co-unsaturated acids resins, pharmaceutics, and bio-degradable/ -compatible polymers, respectively.
Formation Pathways toward 2- and 4-Methylbenzaldehyde via Sequential Reactions from Acetaldehyde over Hydroxyapatite Catalyst
Moteki, Takahiko,Rowley, Andrew T.,Bregante, Daniel T.,Flaherty, David W.
, p. 1921 - 1929 (2017/06/13)
Condensation reactions of biomass derived C2 and C4 aldehydes form both ortho- and para-tolualdehydes (2-MB and 4-MB, respectively). The complete reaction network and the detailed mechanisms, however, have not been fully described. H
Synthesis of C4 and C8 Chemicals from Ethanol on MgO-Incorporated Faujasite Catalysts with Balanced Confinement Effects and Basicity
Zhang, Lu,Pham, Tu N.,Faria, Jimmy,Santhanaraj, Daniel,Sooknoi, Tawan,Tan, Qiaohua,Zhao, Zheng,Resasco, Daniel E.
, p. 736 - 748 (2016/05/09)
A new type of catalyst has been designed to adjust the basicity and level of molecular confinement of KNaX faujasites by controlled incorporation of Mg through ion exchange and precipitation of extraframework MgO clusters at varying loadings. The catalytic performance of these catalysts was compared in the conversion of C2 and C4 aldehydes to value-added products. The product distribution depends on both the level of acetaldehyde conversion and the fraction of magnesium as extraframework species. These species form rather uniform and highly dispersed nanostructures that resemble nanopetals. Specifically, the sample containing Mg only in the form of exchangeable Mg2+ ions has much lower activity than those in which a significant fraction of Mg exists as extraframework MgO. Both the (C6+C8)/C4 and C8/C6 ratios increase with additional extraframework Mg at high acetaldehyde conversion levels. These differences in product distribution can be attributed to 1) higher basicity density on the samples with extraframework species, and 2) enhanced confinement inside the zeolite cages in the presence of these species. Additionally, the formation of linear or aromatic C8 aldehyde compounds depends on the position on the crotonaldehyde molecule from which abstraction of a proton occurs. In addition, catalysts with different confinement effects result in different C8 products.
Cross aldol condensation of acetaldehyde and formaldehyde in the presence of bifunctional systems
Dashko, L. V.,Dmitriev, D. V.,Pestov, S. M.,Flid, V. R.
, p. 1732 - 1737 (2015/02/05)
Liquid-phase cross-aldol condensation of acetaldehyde and formaldehyde in the presence of salts of various saturated and unsaturated linear amines, aromatic amines, diamines, and nitrogen bases, as well as in the presence of substituted piperazines, linear and cyclic amino acids and their derivatives, and nitrogen-containing ionic liquids, was studied. The cross-condensation products were formed in considerable amounts when amine hydrochlorides, N-benzoyl amino acids, and amino acid esters were used as catalyst. The formation of cross-condensation products is favored by increased basicity of the amino nitrogen atom in the salt and of the solvent.
Inorganic ammonium salts and carbonate salts are efficient catalysts for aldol condensation in atmospheric aerosols
Noziere, Barbara,Dziedzic, Pawel,Cordova, Armando
experimental part, p. 3864 - 3872 (2011/07/30)
In natural environments such as atmospheric aerosols, organic compounds coexist with inorganic salts but, until recently, were not thought to interact chemically. We have recently shown that inorganic ammonium ions, NH 4+, act as catalysts for acetal formation from glyoxal, a common atmospheric gas. In this work, we report that inorganic ammonium ions, NH4+, and carbonate ions, CO32-, are also efficient catalysts for the aldol condensation of carbonyl compounds. In the case of NH4+ this was not previously known, and was patented prior to this article. The kinetic results presented in this work show that, for the concentrations of ammonium and carbonate ions present in tropospheric aerosols, the aldol condensation of acetaldehyde and acetone could be as fast as in concentrated sulfuric acid and might compete with their reactions with OH radicals. These catalytic processes could produce significant amounts of polyconjugated, light-absorbing compounds in aerosols, and thus affect their direct forcing on climate. For organic gases with large Henry's law coefficients, these reactions could also result in a significant uptake and in the formation of secondary organic aerosols (SOA). This work reinforces the recent findings that inorganic salts are not inert towards organic compounds in aerosols and shows, in particular, that common ones, such as ammonium and carbonate salts, might even play important roles in their chemical transformations.
NOVEL CATALYST FOR ALDOL CONDENSATION REACTIONS
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Page/Page column 9-11, (2009/05/29)
The present invention presents catalytic systems for aldol condensation reactions, comprising the step of reacting at least one aldehyde or one ketone starting material in the presence of an inorganic ammonium salt, or an aqueous or organic solution prepared from such salt. The efficiency of the catalytic system of the present invention is comparable to those of the classical strong acid and strong base catalysts.
Thermal cylizations of protonated poly-unsaturated aldehydes
Elia, George R.,Childs, Ronald F.,Shaw, Gary S.
, p. 2065 - 2069 (2007/10/02)
Protonated 2,4-hexadienal (1H) and 2,4,6-octatrienal (2H), prepared by protonation of the analogous aldehydes in FSO3H, isomerized to give cyclized products 3H and 4H at 30 deg C and -20 deg C respectively.The rate constants for the cyclization of 1H were measured in both FSO3H and CF3SO3H.It was found that the rate constant for isomerization decreased when CF3SO3H was used as the reation medium.It is suggested that the thermal cyclizations of 1H and 2H involve diprotonated species with protonation occurring on oxygen. 1H and 2H underwent photoisomerization at -78 deg C in FSO3H to yield 5H and 7H respectively.It was found that 5H underwent a cyclization reaction at -40 deg C to give 6H, which subsequently rearranged to give 3H at -10 deg C.However, 7H was found to isomerize to 2H at -50 deg C.The mechanisms of the thermal isomerization are discussed.
Electronic Energy Levels in a Homologous Series of Unsubstituted Linear Polyenes
D'Amico, Kevin L.,Manos, Christopher,Christensen, Ronald L.
, p. 1777 - 1782 (2007/10/02)
Absorption, emission, and exitation spectra of 1,3,5,7-octatetraene, 1,3,5,7,9-decapentaene, and 1,3,5,7,9,11-dodecahexaene have been obtained in room temperature solutions and 77 K glasses.All spectra exibit the chracteristic gap between the origin of the strongly allowed absorption (1Ag --> 1Bu) and the origin of fluorescence (1Ag* --> 1Ag).Comparison with results previously obtained for methyl-substituted polyenes shows that the 1Bu-1Ag* energy gap is a sensitive function of the degree of substitution.Solvent-effects studies have been used to extrapolate transition energies of the unsubstituted polyenes to gas-phase conditions.For the tetraene, pentaene, and hexaene the 1Bu-1Ag* energy differences are 6380, 7050, and 7420 cm-1, respectively.These results are discussed in terms of current theoretical descriptions of polyene electronic states.
