123-25-1Relevant articles and documents
Vanadium(V)-Induced Oxidative Cross-Coupling of Various Boron and Silyl Enolates
Amaya, Toru,Osafune, Yuma,Maegawa, Yusuke,Hirao, Toshikazu
, p. 1301 - 1304 (2017)
Intermolecular oxidative cross-coupling of two different enolates is one of the most useful reactions to synthesize unsymmetrical 1,4-dicarbonyl compounds. In this study, the oxovanadium(V)-induced intermolecular oxidative cross-coupling of enolates afforded unsymmetrical 1,4-dicarbonyl compounds. Various boron and silyl enolates underwent the formation of ketone–ester, ester–ketone, ester–ester, amide–ketone and amide–ester coupling products. These results clearly show the versatility of the present oxidative cross-coupling protocol.
Deactivation of Supported Nickel-Based Hydrogenation Catalysts with Sulfide Ions
Prozorov,Afineevskii,Knyazev,Sukhachev, Ya. P.,Sukhacheva
, p. 2158 - 2162 (2019)
Abstract: Kinetics of the liquid-phase hydrogenation of a multiple carbon bond is studied in an aqueous medium on supported nickel catalysts at different hydrogen pressures in the system under conditions of partly controlled deactivation of the active surface sites with sulfide ions. The pattern of deactivation of the active surface sites of Ni/SiO2 catalysts containing different amounts of the active metal on the surface with sulfide ions in water is determined. The resistance of the studied catalysts to deactivation during the reduction of diethyl maleate (DM) and propen-2-ol-1 is determined experimentally. It is shown that the catalyst is more resistant to deactivation during the hydrogenation of propen-2-ol-1; this finding is attributed to the steric factor. It is found that the hydrogen pressure in the system does not affect the deactivation pattern. Excessive pressure slightly alters the deactivation resistance of the catalyst during the hydrogenation of propen-2-ol-1. It is shown experimentally that the catalytic properties of nickel in liquid-phase hydrogenation reactions can be controlled by introducing small amounts of a catalytic poison into the system at high hydrogen pressures.
Photocatalytic Reaction of Diazo Compounds with Aldehydes
Rybicka-Jasińska,Ciszewski,Gryko
, p. 1671 - 1678 (2016)
Photocatalytic reactions of diazoacetates with aldehydes led to α-alkylated carbonyl compounds instead of the expected cyclopropane derivatives. The reaction requires a dual catalytic system – photocatalysis merged with enamine-iminium catalysis. NMR, EPR, UV/Vis, and ESI-MS analyses provided sufficient data to corroborate the proposed radical mechanism – enamine catalysis merged with photocatalysis. (Figure presented.).
Electrocatalytic Hydrogenation of Diethyl Fumarate. A Simple System Development.
Silva, Jose Ginaldo da,Goulart, Marilia O. F.,Navarro, Marcelo
, p. 7405 - 7410 (1999)
Diethyl fumarate was chosen as a model in search for better conditions to achieve selective electrocatalytic hydrogenation. In addition to carbon felt, several catalytic cathode surfaces have been examined, including Fe, Pt, Ni, Pb, Al, Cu, Zn, and stainless steel. Other variables like current density (58 to 285 mA.dm2), supporting electrolyte (NaCl, KBr, NaBr, NaI, NaF), solution pH* (3.0 to 9.0) and co-solvent (CH3CN, t-BuOH, MeOH and THF) were tried. The majority of the reactions were carried out at constant current in an undivided cell fitted with the chosen working electrode and DSA (RuO2/TiO2) as the auxiliary electrode, in H2O/co-solvent (4:1). The best results for hydrogenation (84 percent chemical yield) were obtained using Fe as cathode, a current density of 175 mA.dm2, in H2O/CH3CN (4:1) at pH* 5.5. NaBr and KBr are also useful electrolytes for hydrogenation. pH* variation does not seem to affect product ratio. THF as co-solvent and NaF as supporting electrolyte should be avoided, as well as carbon felt and Ni as electrodes.
Ultrasound-assisted electrochemical reduction of emulsions in aqueous media
Marken, Frank,Compton, Richard G.,Bull, Steven D.,Davies, Stephen G.
, p. 995 - 996 (1997)
The electrochemical reduction of diethylmaleate, diethylfumarate and diethylacetylene dicarboxylate in the form of microscopic droplets generated by applying power ultrasound to aqueous electrolyte media allows a clean hydrogenation of the carbon-carbon double/triple bond whilst providing a novel and versatile methodology for electrochemistry of insoluble materials in aqueous environments.
Synthesis of a sulfated-group-riched carbonaceous catalyst and its application in the esterification of succinic acid and fructose dehydration to form HMF
Liu, Huihui,Peng, Qian,Ren, Jiawen,Shi, Bianfang,Wang, Yanqin
, p. 2649 - 2656 (2021)
A novel sulfated-group-riched sulfonated carbonaceous catalyst with high acidic strength and adjustable ratio of acidic groups was designed in the paper, where glucose and benzyl chloride were hydrothermally carbonized first followed by sulfonation treatment. Various physicochemical techniques were used to characterize the catalyst such as IR, 13C MAS NMR and XPS spectra, NH3-TPD, XRD patterns and TG curve. Then, it was applied in the esterification of succinic acid and fructose dehydration to form HMF. Compared to commercial Amberlyst-15 catalyst, such carbonaceous solid acid exhibited excellent catalytic activity and thermal stability, which was attributed to its higher amount of sulfonic acid group.
Trimethylsilylketene dialkylacetals in organic synthesis: Reactions with alkyldiazoacetates
Zaitseva, Galina S.,Novikova, Ol'ga P.,Grigoriev, Evgeny V.,Kisin, Alexander V.,Avtomonov, Evgeni V.,Lorberth, Joerg
, p. 175 - 181 (1996)
The reaction of trimethylsilylketene dialkylacetals with alkyldiazoacetates in the presence of Cu(acac)2 or Rh2(OAc)4 results in the formation of alkyl-2,2-dialkoxy-3-trimethylsilylcyclopropane-1-carboxylates 3-8. The cycloaddition proceeds stereoselectively, giving exclusively one of two possible diastereomers. Compounds 4 and 6 are transformed by reaction with LiAlH4 to cyclopropylmethanols 9 and 10 in high yields. All compounds have been characterized by elemental analyses, 1H, 13C NMR and IR spectroscopy.
Vicinal alkylation-carboxymethylation of electron-poor alkenes by radical-chain reactions with O-alkyl O-silyl ketene acetals and their [3+2] annulation by reaction with O-cyclopropylcarbinyl O-silyl ketene acetals
Cai, Yudong,Roberts, Brian P.
, p. 1485 - 1488 (2004)
O-Silyl ketene acetals of the type H2C=C(OR)OSiMe 2But, in which R is a tertiary or secondary alkyl group, react with electron-poor alkenes to bring about vicinal alkylation- carboxymethylation of the latter. When R is a cyclopropyldimethylcarbinyl group such reactions take a more complex course involving ring opening of the cyclopropylcarbinyl radical and lead ultimately to [3+2] annulation of the alkene.
A Synthetic Bilayer Membrane Functionalised with Hydrophobic Vitamin B12 as an Artificial Glutamate Mutase
Murakami, Yukito,Hisaeda, Yoshio,Ohno, Teruhisa
, p. 856 - 858 (1988)
Heptapropyl cobyrinate perchlorate catalysed the conversion of diethyl β-methylaspartate into diethyl glutamate in single-compartment vesicles in the presence of vanadium trichloride as a co-catalyst under aerobic irradiation conditions.
Synthesis and antiischemic activity of dicarboxylic nitroxyalkylamides and nitroxyalkylimides
Fedorov,Bogdanov,Fadeev,Lagodzinskaya
, p. 1119 - 1125 (2014)
A number of dicarboxylic N-(2-nitroxyalkyl)amides and N-(2-nitroxyalkyl)imides were synthesized and their antiischemic activity was studied. The ratio of the areas of necrotic and ischemic zones was used as a criterion for evaluation of antiischemic activity. The maximum values were close to antiischemic activity of Nicorandil, with acute toxicity of compounds synthesized being considerably lower.
