3913-65-3Relevant articles and documents
Oxidation of threonine by the analytical reagent diperiodatocuprate(III) - An autocatalysed reaction
Jose, Timy P.,Tuwar, Suresh M.
, p. 137 - 144 (2007)
The kinetics of Cu(II) autocatalysed oxidation of threonine by well-recognized analytical reagent diperiodatocuprate(III) in aqueous alkaline medium at a constant ionic strength of 0.5 mol dm-3 was studied spectrophotometrically. The reaction between diperiodatocuprate(III) and threonine in alkaline medium exhibits 2:1 stoichiometry (DPC: threonine). The reaction is of first order in each [DPC] and [threonine] and less than unit order in [alkali]. Periodate has retarding effect on the rate of reaction. Ionic strength has negligible effect on the reaction. Increase in dielectric constant of the medium with decrease in the rate of the reaction was observed. The product, Cu(II), catalyses the reaction with a fractional order. The main products were identified by spot test and I.R. A composite mechanism involving the monoperiodatocuptrate(III) (MPC) as the reactive species of the oxidant in uncatalysed and autocatalysed reaction has been proposed. Activation parameters and the reaction constants involved in the different steps of the mechanisms are calculated.
In-situ IR Spectroscopy Study of Reactions of C3 Oxygenates on Heteroatom (Sn, Mo, and W) doped BEA Zeolites and the Effect of Co-adsorbed Water
Najmi, Sean,So, Jungseob,Stavitski, Eli,McDermott, William P.,Lyu, Yimeng,Burt, Sam P.,Hermans, Ive,Sholl, David S.,Sievers, Carsten
, p. 445 - 458 (2020/12/01)
The reactions of acetone and hydroxyacetone over heteroatom doped BEA zeolites (Sn, Mo, and W) in the presence and absence of H2O vapor are investigated using infrared spectroscopy. Acetone is converted to mesityl oxide over Sn-BEA exclusively. At higher temperatures, larger oxygenates such as phorones, aromatics, and coke form. The presence of co-adsorbed water in Sn-BEA suppresses tautomerization. H2O vapor is also beneficial for minimizing coke formation at high temperatures. Hydroxyacetone is converted into 2-hydroxypropanal over Sn-BEA, exhibiting high affinity to Sn sites up to 400 °C. Sn-BEA catalyzes conversion of hydroxyacetone into the enol in the absence of H2O, but exposure to H2O induces the formation of 2-hydroxypropanal and subsequent conversion to acrolein. The Lewis acid descriptors are used to rationalize the reaction pathways. For the isomerization of hydroxyacetone into 2-hydroxypropanal, the hardness of acid sites influences the reaction and correlates with the overall Lewis acidity of the catalysts, respectively. However, the size of the exchanged metal significantly affects aldol condensation, where keto and enol forms of acetone adsorb to active sites simultaneously.
Continuous catalytic process for the selective dehydration of glycerol over Cu-based mixed oxide
Concepción, Patricia,Domine, Marcelo E.,Mazarío, Jaime,Ventura, María
, p. 160 - 175 (2020/04/08)
The selective dehydration of glycerol to hydroxyacetone (acetol) was studied with Cu-based mixed oxides derived from hydrotalcite as catalysts in a continuous flow fix-bed reactor. Catalysts were prepared by co-precipitation and characterized by ICP, N2 adsorption, XRD, NH3-TPD, CO2-TPD, TPR and TEM. Different parameters were investigated to develop the most appropriate material as well as to determine the function of every metallic species. The optimized Cu-Mg-AlOx offered ≈60% acetol selectivity at >90% glycerol conversion (≈80% liquid yield, up to TOS = 9 h). The catalyst could be regenerated by calcination, achieving full activity recovery after five re-cycles. “In-situ” FTIR and XPS measurements evidenced that the presence of Cu, specially the most active Cu1+ species, was essential to carry out the dehydration to acetol with high reaction rates, and to form the preferred intermediate (with C[dbnd]O group); although a minor contribution from Cu0 and Cu2+ species could not be discarded.
METHOD FOR PRODUCING ALDEHYDE
-
Paragraph 0016; 0017-0018, (2017/05/27)
PROBLEM TO BE SOLVED: To provide a new method for producing aldehyde capable of evading reduction under low temperature conditions and having higher selectivity. SOLUTION: Provided is a method for producing aldehyde where activated ester is prepared from carboxylic acid such as saturated fatty acid, unsaturated fatty acid, hydroxy acid, aromatic carboxylic acid and amino acid and an activation ester agent such as halogenated carbonic acid aryl, a carbodiimide-based condensation agent, an imidazole-based condensation agent and a triazine-based condensation agent, and the activated ester is reduced, and being a method for producing aldehyde in which an environmental load is reduce, and having high yield and high selectivity. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
