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A. V. Eremeev V. G. Andrianov I. P. Piskunova 《Chemistry of Heterocyclic Compounds》1978,14(9):963-966
The reaction of some linear and cyclic -keto esters with 3,4-diaminofurazan was investigated. Products of condensation at the keto group and the corresponding furazanodiazepinones were isolated and characterized. The structures of the compounds obtained are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1196–1199, September, 1978. 相似文献
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T. N. Solomoichenko Yu. S. Sadovskii T. M. Prokop’eva E. A. Karpichev I. V. Kapitanov Zh. P. Piskunova V. A. Savelova A. F. Popov 《Theoretical and Experimental Chemistry》2006,42(6):364-370
We have studied the nucleophilicity of the hydroperoxide anion relative to 4-nitrophenyl diethyl phosphonate (NPDEPS) in the
presence of cetyltrimethylammonium bromide (water, 25 °C) while varying the acidity of the medium and the hydroperoxide anion
concentration over a broad range. The increase in the reaction rate when the reaction is transferred to a micellar pseudophase
is as high as ∼10-fold, which is explained by concentration effects. In CTAB micelles, as in water, the hydroperoxide ion
is one of the most effective α-nucleophiles, and the size of the α-effect, characterized by the ratio of the second-order rate constants for reactions of HOO− and OH− anions with NPDEPS, remains practically constant and reaches a value of ∼50-fold.
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Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 6, pp. 357–363, November–December, 2006. 相似文献
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Popov A. F. Lobanova O. V. Savelova V. A. Sadovskii Yu. S. Solomoichenko T. N. Piskunova Zh. P. 《Russian Journal of Organic Chemistry》2002,38(11):1624-1628
For amides belonging to series RCONH2 (I), RCONHMe (II), RCONHPh (III), and RCONMe2 (IV) rate constants k1 (l mol-1 s-1) were determined (in acetonitrile at 25°C) specifying the nucleophilic reactivity of the oxygen atom in amides toward benzoyl chloride and diphenyl chlorophosphate. The lack of substrate selectivity in the reactions in question was established. For equal values of inductive constants * of the R substituents the reactivity sequence of amides with respect to both substrates is the same (I >>
IV >
II, and III >
II), and it does not follow the corresponding sequence of basicities. A conclusion was drawn that both groups of reactions proceed through cyclic transition states resembling reagents: six-membered with amides I and III, and five-membered with amides II and IV. 相似文献
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A series of dimethyl esters and cyclic hydrazides of quinoline-2,3-dicarboxylic acid has been synthesized with different substituents in the benzene ring.Latvian Institute of Organic Synthesis, Riga LV-1006, Merz and Co., 111353, 60048 Frankfurt am Main, Germany. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 86–100, January, 1998. 相似文献
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E. M. Gromov L. V. Piskunova V. V. Tyutin 《Radiophysics and Quantum Electronics》1998,41(12):1051-1055
We present the results of numerical study of the evolution of wave packets and envelope soliton interaction in terms of the third-order nonlinear Schrödinger equation. It is shown that an arbitrary initial pulse evolves to a few solitons and a linear quasiperiodic wave. The interaction of solitons is accompanied by the radiation of part of the wave field in the form of a linear quasiperiodic wave from the interaction region, amplification of the soliton with larger amplitude and attenuation of the soliton with smaller amplitude. 相似文献
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A. V. Piskunov O. Yu. Trofimova M. S. Piskunova I. V. Smolyaninov N. T. Berberova G. K. Fukin 《Russian Journal of Coordination Chemistry》2018,44(2):138-146
Heptacoordinated tin complexes with pentadentate redox-active ligands containing the diiminopyridine fragment combined with two sterically hindered phenolate coordination centers, LSn-Cl2 and L'SnCl2 (L and L' are dianions of deprotonated 2,6-bis[2,4-di-tert-butyl-6-(methylidenylamino) phenol]pyridine and 2,6-bis[2,4-di-tert-butyl-6-(ethylidenylamino)phenol]pyridine, respectively), are synthesized. The molecular and electronic structures of the synthesized compounds were studied by X-ray diffraction analysis (for complex I, CIF file CCDC no. 1557838), a set of spectral methods, and quantum-chemical calculations. The redox properties of the obtained complexes are characterized by cyclic voltammetry. 相似文献
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V. A. Savelova Yu. S. Sadovskii T. N. Solomoichenko T. M. Prokop’eva V. V. Kosmynin Zh. P. Piskunova C. A. Bunton A. F. Popov 《Theoretical and Experimental Chemistry》2008,44(2):101-108
Peroxocarbonate ions HCO 4 ? and CO 4 2? , which are formed in the H2O2/NH4HCO3/HO? system, react with 4-nitrophenyl diethyl phosphonate (I) through a nucleophilic mechanism with rate constants \(k_{HCO_4^ - } = 0.008\) and \(k_{CO_4^{2 - } } = 0.13 L/mol \cdot s\). Comparison of these constants with the corresponding constants of other inorganic anions in their reaction with I in the framework of the Brönsted equation indicates that HCO 4 ? and CO 4 2? are typical α-nucleophiles. 相似文献
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E. Rozhkov I. Piskunova M. Gol'd I. Kalvin'sh 《Chemistry of Heterocyclic Compounds》1998,34(2):222-231
Reaction of N-oxides of dimethyl quinoline-2,3-dicarboxylates with hydrazine and subsequent oxidation with peracetic acid
has been given quinoline-2,3-dicarboxylic acid hydrazide 5-oxides, from which water solublequaternary ammonium salts can be
prepared.
For Communciation 1, see [1].
Latvian Institute of Organic Synthesis, Riga LV-1006. Merz and Co., 111353, 60048 Frankfurt am Main Germany. Translated from
Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 247–257, February, 1998. 相似文献