553-90-2Relevant articles and documents
Cyclization of Dimethyl Oxalate upon Electron Impact
Liehr, J. G.,Larka, E. A.,Beynon, J. H.
, p. 34 - 36 (1981)
Isotope labelling experiments and also consecutive fragmentation investigations of metastable ions, a novel technique in mechanistic studies, have been carried out to elucidate structure and genesis of the m/z 45 ions from dimethyl oxalate as well as dimethyl carbonate.It is shown that the formation of the m/z 45 ions, CH3O(1+)=CH2, in the mass spectra of these compounds arises via single step processes.Mechanisms involving hydrogen transfer and subsequent formation of cyclic intermediates which then collapse to give CH3O(1+)=CH2 directly from molecular ions are suggested.No evidence was found for a two-step fragmentation route to m/z 45 from the molecular ions of either dimethyl oxalate or dimethyl carbonate.
Catalytic Synthesis of Oxalate Esters
Current, Steven P.
, p. 1779 - 1780 (1983)
A new catalyst system, palladium(II) acetate, cobalt(II) acetate, triphenylphosphine, and 1,4-benzoquinone, produces oxalate esters in high selectivity from carbon monoxide, oxygen, and alcohol.Up to 140 mol of dimethyl oxalate is obtained per mole of palladium while only traces of dimethyl carbonate or methyl formate are formed.
Catalyst design criteria and fundamental limitations in the electrochemical synthesis of dimethyl carbonate
?ari?, Manuel,Davies, Bethan Jane Venceslau,Schj?dt, Niels Christian,Dahl, S?ren,Moses, Poul Georg,Escudero-Escribano, María,Arenz, Matthias,Rossmeisl, Jan
, p. 6200 - 6209 (2019)
Dimethyl carbonate is an environmentally friendly precursor in various chemical reactions and is currently synthesized by hazardous processes. An electrocatalytic approach could result in a process abiding to the principles of Green Chemistry. Herein we demonstrate how density functional theory (DFT) calculations and experiment advance our understanding of electrocatalytic production of chemicals. Using density functional theory, we form design criteria for dimethyl carbonate electrosynthesis on metallic surfaces. The criteria are based on adsorption free energies of reactants and reaction energies of possible products. The design criteria allow us to identify copper as an interesting candidate for the electrode material as it is classified as being selective to dimethyl carbonate and requires ≈1 V lower potential than a gold electrode. By further addressing electrode stability copper was found to dissolve and produce copper-carbonyl species which lead to dimethyl carbonate as a consequence of a reaction in the solution, therefore not occurring by surface electrocatalysis. This shows that the design criteria presented herein are necessary but not sufficient requirements that the ideal electrode should satisfy.
Remarkable Decrease in Overpotential of Oxalate Formation in Electrochemical CO2 Reduction by a Metal-Sulfide Cluster
Kushi, Yoshinori,Nagao, Hirotaka,Nishioka, Takanori,Isobe, Kiyoshi,Tanaka, Koji
, p. 1223 - 1224 (1995)
Triangular metal-sulfide cluster, 3(μ3-S)2>2+ and 3(μ3-S)2>2+, catalyse the electrochemical CO2 reduction to selectively produce oxalate at -1.30 and -0.70 V (vs.Ag/AgCl), respectively, in MeCN.
Active Pd(II) complexes: Enhancing catalytic activity by ligand effect for carbonylation of methyl nitrite to dimethyl carbonate
Tan, Hong-Zi,Wang, Zhi-Qiao,Xu, Zhong-Ning,Sun, Jing,Chen, Zhe-Ning,Chen, Qing-Song,Chen, Yumin,Guo, Guo-Cong
, p. 3785 - 3790 (2017)
Palladium (Pd)-based catalysts have been widely used for carbonylation of methyl nitrite to dimethyl carbonate (DMC), but a high-performance chloride free catalyst combining both excellent carbon monoxide (CO) conversion and DMC selectivity has not been developed yet. In this work, a chloride free, Pd-based catalyst with good activity and selectivity (conversion of CO: 60.1%, selectivity to DMC: 99.9%) has been successfully fabricated. By thorough characterization and analysis, it is found that the good catalytic activity is positively correlated with the high oxidation states of the Pd species, which could be tuned by their ability to accept the backdonation electron of the ligands. The strong electron backdonation from Pd to π? antibonding orbitals of the ligand in the palladium acetylacetonate [Pd(acac)2] complex accelerates the step where Pdδ+ reoxidizes to Pd(ii), resulting in the higher catalytic activity. In addition, a catalytic mechanism was proposed based on the results of X-ray photoelectron spectroscopy and in situ diffuse reflectance infrared spectroscopy. This work not only explains the positive relationship between the catalytic activity and the oxidation state of the Pd species, but also provides a new way to enhance catalytic performance by utilizing the abilities of accepting the backdonation electron of the ligands.
Low-temperature synthesis of α-alumina nanosheets on microfibrous-structured Al-fibers for Pd-catalyzed CO oxidative coupling to dimethyl oxalate
Wang, Chunzheng,Xu, Weisong,Qin, Zhengxing,Liu, Xinmei,Mintova, Svetlana
, p. 158 - 166 (2020)
We reported the low-temperature synthesis of α-Al2O3 nanosheets on the microfibrous-structured Al-fibers at 800 oC. The boehmite (AlOOH) nanosheets were initially formed on the Al-fibers through in situ endogenous growth. Then the AlOOH/Al-fibers was transformed to the α-Al2O3/Al-fibers composite at 800 °C by a single heating step. The low-temperature phase transformation was tentatively attributed to the Al metal in the AlOOH/Al-fibers. Palladium was then dispersed on the α-Al2O3/Al-fibers composite, and the resulting Pd/α-Al2O3/Al-fibers catalyst was examined in the strongly exothermic CO oxidative coupling to dimethyl oxalate (DMO) reaction. High CO conversion of 58percent and DMO selectivity of 95percent were obtained and maintained for at least 150 h using a feedgas of CH3ONO / CO / N2 (1 / 1.4 / 7.6, mole) at 150 oC with a gas hourly space velocity of 20,000 mL g―1 h―1. Computational fluid dynamics calculations and experimental results indicated that the Pd/α-Al2O3/Al-fibers catalyst remarkably decreased the hot-spot temperature of catalyst bed due to its enhanced thermal conductivity.
Selectivity Control of Carbonylation of Methanol to Dimethyl Oxalate and Dimethyl Carbonate over Gold Anode by Electrochemical Potential
Funakawa, Akiyasu,Yamanaka, Ichiro,Takenaka, Sakae,Otsuka, Kiyoshi
, p. 5346 - 5347 (2004)
New and unique electrocatalysis of gold for the carbonylation of methanol to dimethyl oxalate (DMO) and dimethyl carbonate (DMC) was found. The selectivity to DMO and DMC could be controlled over gold anode by electrochemical potential, as you like. Drastic changes of gold electrocatalysis was due to changes of the oxidation state of gold, Au0 or Au3+. Copyright
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Friess,Miller
, p. 2611 (1950)
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New series of γ-pyrone based podands: Synthesis, characterization and study of their application in acetate salts cation trapping for nucleophilic substitution reactions
Teimuri-Mofrad, Reza,Aghaiepour, Alireza,Rahimpour, Keshvar
, p. 121 - 132 (2019)
Dialkyl 4-oxo-4H-pyran-2,6-dicarboxylates are synthesized via esterification of chelidonic acid or via intramolecular cyclization of dialkyl-2,4,6-trioxoheptanedioates. Reaction of the dialkyl 4-oxo-4H-pyran-2,6-dicarboxylates with a variety of glycol monoalkyl ethers produces a series of new podands in good yields. To demonstrate the use of these podands in cation trapping, nucleophilic substitution reactions are carried out with various acetate salts. The results indicate that the cation diameter’s compatibility with binding site leads to the best yield of reaction.
Pd/Mg(OH)2 Heterogeneous Nanocatalysts Synthesized by a Facile One-Pot Hydrothermal Method for CO Direct Esterification to Dimethyl Oxalate
Lin, Xiao-Qi,Wang, Zhi-Qiao,Xu, Zhong-Ning,Guo, Guo-Cong
, p. 3213 - 3219 (2021)
Pd-based heterogeneous nanocatalysts have wide application in chemical industry. However, the traditional synthesis process contains multi-steps such as impregnation, dry, calcination and reduction. The pre-synthesis nanoparticles process can reduce the steps, but need to remove the surfactants, which are added in the synthesis process. In this work, a facile one-pot hydrothermal synthesis process named as single molecular precursor method was successfully developed to prepare Pd/Mg(OH)2 heterogeneous nanocatalysts with clean surface. The as-synthesized Pd/Mg(OH)2 heterogeneous nanocatalysts show excellent performance for CO direct esterification to dimethyl oxalate (DMO). The WTY (weight time yield) of DMO can reach the high-performance of 2544?g?kgcat.?1?h?1, while the conversion of CO is 62.6% and selectivity to DMO is 90.8%. The single molecular precursor method developed by this work can be extended to other supported noble metal nanocatalysts. Graphic Abstract: [Figure not available: see fulltext.].
Ultralow-Molecular-Weight Stimuli-Responsive and Multifunctional Supramolecular Gels Based on Monomers and Trimers of Hydrazides
Wu, Dehua,Song, Jintong,Qu, Lang,Zhou, Weilan,Wang, Lei,Zhou, Xiangge,Xiang, Haifeng
supporting information, p. 3370 - 3378 (2020/10/02)
The simpler, the better. A series of simple, neutral and ultralow-molecular-weight (MW: 140–200) hydrazide-derived supramolecular gelators have been designed and synthesized in two straightforward steps. For non-conjugated cyclohexane-derived hydrazides, their monomers can self-assemble to form gels through intermolecular hydrogen bonds and dipole-dipole interactions. Significantly, conjugated phthalhydrazide can self-aggregate into planar and circular trimers through intermolecular hydrogen bonds and then self-assemble to form gels through intermolecular π–π stacking interactions. It is interesting that these simple gelators exhibit unusual properties, such as self-healing, multi-response fluorescence, and visual and selective recognition of chiral (R)/(S)-1,1′-binaphthalene-2,2′-diamine and S2? through much different times of gel re-formation and blue-green color change, respectively. These results underline the importance of supramolecular gels and extend the scope of supramolecular gelators.
