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74-89-5Relevant articles and documents
A Plausible Prebiotic Origin of Glyoxylate: Nonenzymatic Transamination Reactions of Glycine with Formaldehyde
Mohammed, Fiaz S.,Chen, Ke,Mojica, Mike,Conley, Mark,Napoline, Jonathan W.,Butch, Christopher,Pollet, Pamela,Krishnamurthy, Ramanarayanan,Liotta, Charles L.
, p. 93 - 97 (2017)
Glyoxylate has been postulated to be an important prebiotic building block. However, a plausible prebiotic availability of glyoxylate has not as yet been demonstrated. Herein we report the formation of glyoxylate by means of a transamination reaction between glycine and formaldehyde in water at 50 °C and 70 °C at pH 8 and 6, respectively. The reaction was followed by means of 13C NMR and high-resolution mass spectrometry employing both unlabeled and 13C-labeled reactants. Other products accompanying the transamination process include serine, sarcosine, N,N-dimethylglycine, and carbon dioxide/bicarbonate. The mechanisms for the formation of glyoxylate and accompanying products are discussed. 1 Introduction 2 Background 3 Results and Discussion 3.1 Reaction of 13C-Labeled Glycine with Formaldehyde at pH 8 3.2 Reaction of 13C-Labeled Glycine with Formaldehyde at pH 6 3.3 Serine-Promoted Decarboxylation of Glyoxylate 4 Conclusions.
Kinetics of the cross reaction between amidogen and methyl radicals
Jodkowski, Jerzy T.,Ratajczak, Emil,Fagerstroem, Kjell,Lund, Anders,Stothard, Nigel D.,et al.
, p. 63 - 71 (1995)
For the title reaction, the pressure dependent rate coefficients were studied at 298 K using two complementary experimental techniques.Pulse radiolysis combined with UV absorption was employed at pressures between 500 and 1000 mbar, while a fast-flow system with a quadrupole mass spectrometer (at low ionization energies) was applied at pressures in the range of 0.7-5.1 mbar.The fall-off curve was constructed in terms of Troe's analysis, and the following high- and low-pressure limiting rate coefficients were derived: krec, infinite = (1.3 +/- 0.3) * 10-10 * T/300)0.42 cm3 molecule-1 s-1 and krec,0 = (1.8 +/- 0.5)*10-27*(T/300)-3.85 cm6 molecule-2 s-1.
Transformative Evolution of Organolead Triiodide Perovskite Thin Films from Strong Room-Temperature Solid-Gas Interaction between HPbI3-CH3NH2 Precursor Pair
Pang, Shuping,Zhou, Yuanyuan,Wang, Zaiwei,Yang, Mengjin,Krause, Amanda R.,Zhou, Zhongmin,Zhu, Kai,Padture, Nitin P.,Cui, Guanglei
, p. 750 - 753 (2016)
We demonstrate the feasibility of a nonsalt-based precursor pair - inorganic HPbI3 solid and organic CH3NH2 gas - for the deposition of uniform CH3NH3PbI3 perovskite thin films. The strong room-temperature solid-gas interaction between HPbI3 and CH3NH2 induces transformative evolution of ultrasmooth, full-coverage perovskite thin films at a rapid rate (in seconds) from nominally processed rough, partial-coverage HPbI3 thin films. The chemical origin of this behavior is elucidated via in situ experiments. Perovskite solar cells, fabricated using MAPbI3 thin films thus deposited, deliver power conversion efficiencies up to 18.2%, attesting to the high quality of the perovskite thin films deposited using this transformative process.
Synthesis of Ultrafine Silver Nanoparticles on the Surface of Fe3O4@SiO2@KIT-6-NH2 Nanocomposite and Their Application as a Highly Efficient and Reusable Catalyst for Reduction of Nitrofurazone and Aromatic Nitro Compounds Under Mild Conditions
Ansari, Sara,Khorshidi, Alireza,Shariati, Shahab
, p. 410 - 418 (2019)
Uniform dispersion of ultrafine spherical silver nanoparticles (NPs) was obtained over the surface of Fe3O4@SiO2@KIT-6 core–shell support via functionalization of the mesoporous KIT-6 shell by aminopropyltriethoxysilane, followed by coordination of Ag+ ions and in situ chemical reduction with sodium borohydride. The obtained hybrid material, Fe3O4@SiO2@KIT-6-Ag nanocomposite, was fully characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, and used as an efficient catalyst for selective reduction of nitroaromatic compounds in aqueous solution at ambient temperature and neutral pH [nine examples, apparent rate constants at 25?°C, k (min?1), 0.112–0.628]. As a non-aromatic example, nitrofurazone which is a cytotoxic antibiotic was also reduced selectively at nitro group without reduction of other functionalities. Fe3O4@SiO2@KIT-6-Ag NPs also showed potential ability to act as catalyst for reduction of nitromethane in aqueous solution which can provide a colorimetric method for detection of nitromethane in solution down to 0.9 × 10?4?mol?L?1. Fe3O4@SiO2@KIT-6-Ag nanocomposite was also screened for its antibacterial activity, and satisfactory results were obtained in comparison with drug references including Tetracycline, Chloramphenicol and Cefotaxime as positive controls, on gram negative Escherichia coli and Pseudomonas aeroginosa. Ease of recycling of the Fe3O4@SiO2@KIT-6-Ag is another benefit of this nanocatalyst. Under the optimized conditions, the recycled catalyst showed 15% loss of efficiency after five successive runs. Graphical Abstract: [Figure not available: see fulltext.].
Catalytic reduction of cis-dimethyldiazene by the [MoFe3S4]3+ clusters. The four-electron reduction of a N = N bond by a nitrogenase-relevant cluster and implications for the function of nitrogenase
Malinak, Steven M.,Simeonov, Anton M.,Mosier, Patrick E.,McKenna, Charles E.,Coucouvanis, Dimitri
, p. 1662 - 1667 (1997)
The catalytic reduction of cis-dimethyldiazene by the (Et4N)2[(Cl4-cat)(CH3CN)MoFe3S4Cl3] cluster (Cl4-cat = tetrachlorocatecholate) is reported. Unlike the reduction of cis-dimethyldiazene by the Fe/Mo/S center of nitrogenase, which yields methylamine, ammonia, and methane (the latter from the reduction of the C-N bond), the reduction of cis-dimethyldiazene by the synthetic cluster yields exclusively methylamine. In separate experiments, it was shown that the C-N bond of methylamine is not reduced by the [MoFe3S4]3+ core, perhaps accounting for the differences observed between the biological and abiological systems. 1,2-Dimethylhydrazine, a possible partially reduced intermediate in the reduction of cis-dimethyldiazene, was also shown to be reduced to methylamine. Interaction of methylamine with the Mo atom of the cubane was confirmed through the synthesis and structural characterization of (Et4N)2[(Cl4-cat)(CH3NH2)MoFe3S4Cl3]. Phosphine inhibition studies strongly suggest that the Mo atom of the [MoFe3S4]3+ core, which has a Mo coordination environment very similar to that in nitrogenase, is responsible for the binding and activation of cis-dimethyldiazene. The reduction of a N = N bond exclusively at the heterometal site of a nitrogenase-relevant synthetic compound may have implications regarding the function of the nitrogenase Fe/Mo/S center, particularly in the latter stages of dinitrogen reduction.
An Electrochemical Approach to Designer Peptide α-Amides Inspired by α-Amidating Monooxygenase Enzymes
Lin, Yutong,Malins, Lara R.
supporting information, p. 11811 - 11819 (2021/08/16)
Designer C-terminal peptide amides are accessed in an efficient and epimerization-free approach by pairing an electrochemical oxidative decarboxylation with a tandem hydrolysis/reduction pathway. Resembling Nature's dual enzymatic approach to bioactive primary α-amides, this method delivers secondary and tertiary amides bearing high-value functional motifs, including isotope labels and handles for bioconjugation. The protocol leverages the inherent reactivity of C-terminal carboxylates, is compatible with the vast majority of proteinogenic functional groups, and proceeds in the absence of epimerization, thus addressing major limitations associated with conventional coupling-based approaches. The utility of the method is exemplified through the synthesis of natural product acidiphilamide A via a key diastereoselective reduction, as well as bioactive peptides and associated analogues, including an anti-HIV lead peptide and blockbuster cancer therapeutic leuprolide.
Degradation of Organic Cations under Alkaline Conditions
You, Wei,Hugar, Kristina M.,Selhorst, Ryan C.,Treichel, Megan,Peltier, Cheyenne R.,Noonan, Kevin J. T.,Coates, Geoffrey W.
supporting information, p. 254 - 263 (2020/12/23)
Understanding the degradation mechanisms of organic cations under basic conditions is extremely important for the development of durable alkaline energy conversion devices. Cations are key functional groups in alkaline anion exchange membranes (AAEMs), and AAEMs are critical components to conduct hydroxide anions in alkaline fuel cells. Previously, we have established a standard protocol to evaluate cation alkaline stability within KOH/CD3OH solution at 80 °C. Herein, we are using the protocol to compare 26 model compounds, including benzylammonium, tetraalkylammonium, spirocyclicammonium, imidazolium, benzimidazolium, triazolium, pyridinium, guanidinium, and phosphonium cations. The goal is not only to evaluate their degradation rate, but also to identify their degradation pathways and lead to the advancement of cations with improved alkaline stabilities.
Electrochemical Reductive N-Methylation with CO2Enabled by a Molecular Catalyst
Rooney, Conor L.,Wu, Yueshen,Tao, Zixu,Wang, Hailiang
supporting information, p. 19983 - 19991 (2021/12/01)
The development of benign methylation reactions utilizing CO2 as a one-carbon building block would enable a more sustainable chemical industry. Electrochemical CO2 reduction has been extensively studied, but its application for reductive methylation reactions remains out of the scope of current electrocatalysis. Here, we report the first electrochemical reductive N-methylation reaction with CO2 and demonstrate its compatibility with amines, hydroxylamines, and hydrazine. Catalyzed by cobalt phthalocyanine molecules supported on carbon nanotubes, the N-methylation reaction proceeds in aqueous media via the chemical condensation of an electrophilic carbon intermediate, proposed to be adsorbed or near-electrode formaldehyde formed from the four-electron reduction of CO2, with nucleophilic nitrogenous reactants and subsequent reduction. By comparing various amines, we discover that the nucleophilicity of the amine reactant is a descriptor for the C-N coupling efficacy. We extend the scope of the reaction to be compatible with cheap and abundant nitro-compounds by developing a cascade reduction process in which CO2 and nitro-compounds are reduced concurrently to yield N-methylamines with high monomethylation selectivity via the overall transfer of 12 electrons and 12 protons.
Pd Nanoparticles Assembled on Metalporphyrin-Based Microporous Organic Polymer as Efficient Catalyst for Tandem Dehydrogenation of Ammonia Borane and Hydrogenation of Nitro Compounds
Zou, Zhijuan,Jiang, Yaya,Song, Kunpeng
, p. 1277 - 1286 (2019/11/20)
Abstract: Metalporphyrin-based porous polymers supporting high dispersed Pd nanoparticle (NP) catalysts (HUST-1-Pd) were prepared with a novel solvent-knitting hyper-crosslinked polymer method using 5-, 10-, 15-, and 20-tetraphenylporphyrin (TPP) as building blocks. The N2 sorption isotherms of the catalysts show that the HUST-1-Pd possesses many ultra-micropores and continuous mesopores. The NPs are assembled on tetraphenylporphyrin structures and show Pd-N4 composition-dependent catalysis for methanolysis of ammonia borane (AB) and hydrogenation of aromatic nitro compounds to primary amines in methanol solutions at room temperature. The nano-palladium reduced by NaBH4 has efficient catalytic activity for AB methanolysis. A variety of R-NO2 derivatives were reduced selectively into R-NH2 via palladium catalyzed tandem reactions with 5–30?min of reaction time with conversion yields reaching up to 90%. The derivatives also give excellent recycling performance (more than 10 times). Furthermore, the turnover frequency (TOF) can reach 87,209?h?1. The HUST-1-Pd compounds represent a unique metal catalyst for hydrogenation reactions in a green environment without using pure hydrogen. Graphic Abstract: A monodisperse Pd NPs embed in porphyrin-based microporous organic polymer was reported to catalyse the tandem dehydrogenation of ammonia borane and hydrogenation of R-NO2 to R-NH2 at room temperature. The catalyst is efficient and reusable in an environment-friendly process with short reaction times and high yields.[Figure not available: see fulltext.]
MOF-Derived Cu-Nanoparticle Embedded in Porous Carbon for the Efficient Hydrogenation of Nitroaromatic Compounds
Qiao, Chenxia,Jia, Wenlan,Zhong, Qiming,Liu, Bingyu,Zhang, Yifu,Meng, Changgong,Tian, Fuping
, p. 3394 - 3401 (2020/05/19)
Abstract: Novel Cu-nanoparticles (NPs) embedded in porous carbon materials (Cu@C-x) were prepared by one-pot pyrolysis of metal–organic frameworks (MOF) HKUST-1 at different temperatures. The obtained material Cu@C-x was used as a cost-effective catalyst for the hydrogenation of nitrobenzene using NaBH4 as the reducing agent under mild reaction conditions. By considering the catalyst preparation and the catalytic activity, a pyrolysis temperature of 400?°C was finally chosen to synthesize the optimal catalyst. When the aromatic nitro compounds with reducible groups, such as cyano, halogen, and alkyl groups, were tested in this catalytic hydrogenation, an excellent selectivity approaching 100% was achieved. In the recycling experiment, a significant decrease in nitrobenzene conversion was observed in the third cycle, mainly due to the very small amount of catalyst employed in the reaction. Hence, the easily prepared and cost-effective Cu@C-400 catalyst fabricated in this study demonstrates potential for the applications in selective reduction of aromatic nitro compounds. Graphic Abstract: The catalyst Cu@C-400 exhibited 100?% conversion and high selectivity for the hydrogenation of industrially relevant nitroarenes.[Figure not available: see fulltext.].