3031-75-2Relevant articles and documents
Rewsin et al.
, (1955)
A new binuclear oxovanadium(v) complex as a catalyst in combination with pyrazinecarboxylic acid (PCA) for efficient alkane oxygenation by H 2O2
Sutradhar, Manas,Shvydkiy, Nikita V.,Guedes Da Silva, M. Fátima C.,Kirillova, Marina V.,Kozlov, Yuriy N.,Pombeiro, Armando J. L.,Shul'Pin, Georgiy B.
supporting information, p. 11791 - 11803 (2013/09/02)
A new binuclear oxovanadium(v) complex [{VO(OEt)(EtOH)}2L] (1) where H4L is bis(2-hydroxybenzylidene)terephthalohydrazide has been synthesized and fully characterized. The combination of 1 with pyrazine-2-carboxylic acid (PCA; a cocatalyst) affords a catalytic system for the efficient oxidation of saturated hydrocarbons, RH, with hydrogen peroxide and air in acetonitrile solution at 50°C to produce alkyl hydroperoxides, ROOH, as the main primary products. Very high turnover numbers (TONs) have been attained in this reaction: for example, after 2220 min, TON = 44 000 and initial TOF (turnover frequency) = 3300 h-1 per molecule of complex 1. The estimated activation energy of the cyclohexane oxygenation in the presence of 1/PCA is Ea = 16 ± 2 kcal mol-1. This value is identical to that obtained for the cyclohexane oxidation with H 2O2 catalyzed by the (n-Bu4N)[VO 3]/PCA combination (17 ± 2 kcal mol-1). The dependences of initial oxidation rates W0 on the initial concentrations of all components of the reaction mixture have been determined. Based on these kinetic data and on the regio- and bond-selectivity parameters measured in the oxidation of linear and branched alkanes a mechanism of the oxidation has been proposed which includes the generation of hydroxyl radicals in the crucial stage. The Royal Society of Chemistry.
Unusual chemoselective addition of diisopropylzinc to 2,2′-bipyridine-5,5′-dicarbonyl compounds in the 2-position and autoxidative reconversion with carbon-carbon bond cleavage
Tanji, Shigehisa,Shibata, Takanori,Sato, Itaru,Soai, Kenso
, p. 217 - 218 (2007/10/03)
The chemoselective addition of diisopropylzinc to 2,2′-bipyridine-5,5′-dicarbonyl compounds in the 2-position and autoxidative reconversion with carbon-carbon bond cleavage was presented. It was shown that i-Pr2Zn do not add to the aldehyde moiety but to the 2-position of the bipyridine to afford possessing a quaternary carbon atom in a yield of 69%. It was found that the i-Pr2Zn does not add to the aldehyde but to the 2-position of the bipyridine ring by destroying the aromaticity of the pyridine ring.
Oxidations by the reagent 'O2-H2O2-vanadium complex-pyrazine-2-carboxylic acid' - VIII. Efficient oxygenation of methane and other lower alkanes in acetonitrile
Nizova, Galina V.,Suess-Fink, Georg,Shul'pin, Georgiy B.
, p. 3603 - 3614 (2007/10/03)
Methane, ethane, propane, n-butane and isobutane can be readily oxidized in acetonitrile solution by air and H2O2 at 20-75°C using the catalytic system [n-Bu4N]VO3/pyrazine-2-carboxylic acid, Apart from alkyl hydroperoxides which are the primary oxidation products, more stable derivatives (alcohols, aldehydes or ketones and carboxylic acids) are obtained with high total turnover numbers (e.g., at 75°C after 4 h: 420 for methane and 2130 for ethane). It was shown in the case of ethane and cyclohexane that alkanes do not yield oxygenated products in the absence of air. The cyclohexane oxidation under an 18O2 atmosphere showed a high degree of 18O incorporation into the oxygenated products. Thus in the oxidation reaction described here H2O2 is only the promoter while O2 is the 'true' oxidant.
