RAS Institute of Organic Chemistry

Oktyabrya, Russia

RAS Institute of Organic Chemistry

Oktyabrya, Russia
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Samsonov V.A.,RAS Institute of Organic Chemistry
Russian Journal of Organic Chemistry | Year: 2017

The reaction of 2,6-bis(hydroxyimino)cyclohexan-1-one with aldehydes and ammonia afforded 2-substituted 4-hydroxyimino-4,5,6,7-tetrahydro-1H-benzimidazol-1-ols which were hydrolyzed to 1-hydroxy- 2-R-1,5,6,7-tetrahydro-4H-benzimidazol-4-ones. The N-hydroxy group in the latter can readily by removed by the action of chloroacetone in the presence of a base (potassium carbonate or triethylamine); as a result, 2-substituted 1,5,6,7-tetrahydro-4H-benzimidazol-4-ones were obtained. © 2017, Pleiades Publishing, Ltd.


Vlasov V.M.,RAS Institute of Organic Chemistry
Journal of Physical Organic Chemistry | Year: 2017

The changes of the free energy of activation δΔG≠ exp and the activation entropy δΔS≠ in the framework of the isokinetic relationship δΔG≠ exp versus (Tiso - Texp) δΔS≠ were explored quantitatively to predict the isokinetic temperature Tiso for the aromatic nucleophilic substitution reactions in solution. © 2017 John Wiley & Sons, Ltd.


Abstract: A study was made of the influence of the substituent effects on the activation parameters changes in the SNAr reactions. It involved the analysis of both the free energy of activation ∆G≠ from the reaction rate constants at single temperature and δ∆G≠ reaction constants obtained by the Hammett-like equation. The analysis of the internal enthalpy constants δ∆Hint ≠and the Hammett ρ constants allowed one to prove the existence of dependence between the δ∆Hint ≠and ρ values in which the high magnitudes of these constants indicate a change in the mechanism from a polar SNAr pathway to a SET (single electron transfer). Graphical abstract: [Figure not available: see fulltext.] © 2017 Springer-Verlag Wien


Lathe R.,RAS Institute of Organic Chemistry | Kotelevtsev Y.,Queens Medical Research Institute
Steroids | Year: 2014

Steroid/sterol-binding receptors and enzymes are remarkably promiscuous in the range of ligands they can bind to and, in the case of enzymes, modify - raising the question of how specific receptor activation is achieved in vivo. Estrogen receptors (ER) are modulated by 27-hydroxycholesterol and 5α-androstane-3β,17β-diol (Adiol), in addition to estradiol (E2), and respond to diverse small molecules such as bisphenol A. Steroid-modifying enzymes are also highly promiscuous in ligand binding and metabolism. The specificity problem is compounded by the fact that the steroid core (hydrogenated cyclopentophenanthrene ring system) has several planes of symmetry. Ligand binding can be in symmetrical East-West (rotation) and North-South (inversion) orientations. Hydroxysteroid dehydrogenases (HSDs) can modify symmetrical 7 and 11, also 3 and 17/20, positions, exemplified here by yeast 3α,20β-HSD and mammalian 11β-HSD and 17β-HSD enzymes. Faced with promiscuity and symmetry, other strategies are clearly necessary to promote signaling selectivity in vivo. Gating regulates hormone access via enzymes that preferentially inactivate (or activate) a subclass of ligands, thereby governing which ligands gain receptor access - exemplified by 11β-HSD gating cortisol access to the mineralocorticoid receptor, and P450 CYP7B1 gating Adiol access to ER. Counter-intuitively, the specificity of steroid/sterol action is achieved not by intrinsic binding selectivity but by the combination of local metabolism and binding affinity. © 2014 Elsevier Inc. All rights reserved.


Salakhutdinov N.F.,RAS Institute of Organic Chemistry
Mini reviews in medicinal chemistry | Year: 2010

This review discusses the most active natural and synthetic curarelike compounds demonstrating myorelaxants activity. The data are grouped according to chemical structures, namely, quinoline and isoquinoline myorelaxants, myorelaxants with saturated heterocyclic or alkylamine fragments, myorelaxants with a steroid framework, natural and synthetic alkaloid myorelaxants.


Gataullin R.R.,RAS Institute of Organic Chemistry
Russian Journal of Organic Chemistry | Year: 2013

The review considers new advances in the synthesis of indoles annulated with cycloalkanes. © 2013 Pleiades Publishing, Ltd.


Vlasov V.M.,RAS Institute of Organic Chemistry
New Journal of Chemistry | Year: 2010

Changes of the activation parameters, ΔH‡ and ΔS‡, in the SN2, SNV, Ad N, SNAr and acyl-transfer reactions with phenol, aniline and pyridine nucleophiles in various solvents were correlated with σ constants of the substituents in the aromatic ring of the nucleophiles. The resultant δΔH‡ and δΔS ‡ reaction constants are linearly related for variations of substituents at the nucleophile. Correlation of δΔH ‡vs. δΔS‡ allow the estimation of the contribution of changes of the internal enthalpy, δΔH ‡ int, to the enthalpy reaction constant, δΔH‡, which gives a single linear dependence on the Hammett ρ reaction constants for all bimolecular nucleophilic reactions. The deviations from dependence of δΔH‡ intvs. ρ can be interpreted in terms of changes of the transition state structure or reaction mechanism. The results obtained show that the substituent effects in the nucleophiles on the charge development in the transition state are governed by the magnitude of δΔH ‡ int. © 2010 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.


Vlasov V.M.,RAS Institute of Organic Chemistry
New Journal of Chemistry | Year: 2010

Changes of the activation parameters, ΔH≠ and ΔS≠, in the SN2, SNAr and acyl-transfer reactions with charged and neutral nucleophiles in various solvents were correlated with σ constants of the substituents in the aromatic ring of the substrates. The resultant δΔH≠ and δΔS≠ reaction constants are linearly related for variations of substituents at the substrate. Correlation of δΔH ≠vs. δΔS≠ allows one to estimate the contribution of changes of the internal enthalpy, δΔH≠int, to the enthalpy reaction constant, δΔH≠, which gives a single linear dependence on the Hammett ρ reaction constants for all bimolecular nucleophilic reactions. The deviations from dependence of δΔH≠intvs. ρ can be interpreted in terms of changes of the transition state structure or reaction mechanism. The results obtained show that the substituent effects in the substrates and nucleophiles on the charge development in the transition state are governed by the magnitude of δΔH≠int. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.


Klabunovskii E.I.,RAS Institute of Organic Chemistry
Russian Journal of Organic Chemistry | Year: 2012

The review analyzes factors responsible for the appearance of homochirality in determinate processes, as well as the role of indeterminate processes in the earth biosphere and space and their effect on the biosphere evolution functionality. Modern views on the significance of homochirality for the evolution of earth biosphere are considered. © Pleiades Publishing, Ltd., 2012.


Variation of the activation parameters in the S N2, acyl-transfer, S NAr, S NV, and Ad N reactions offers a uniquely useful probe for the mechanistic features of these reactions in solution. New approach uses the substituent effects on the aromatic ring to the variation of the activation parameters, ΔH ≠ and ΔS ≠, in the above reactions in the frameworks of the Hammett-like equations in order to evaluate the resultant δΔH ≠ and δΔS ≠ reaction constants. Compensation relationships of δΔH ≠ versus δΔS ≠ allow one to estimate the contribution of changes of the internal enthalpy, δΔH ≠ int, to the enthalpy reaction constant, δΔH ≠, that is inherent to bimolecular nucleophilic reactions and gives a single linear dependence on the Hammett ρ reaction constants for these reactions. The deviations from dependence of δΔH ≠ int versus ρ serve as useful points of interpretation of changes of the transition state structure or reaction mechanism. The results obtained show that the substituent effects in the substrates, nucleophiles, and leaving groups on the mechanistic features in bimolecular nucleophilic reactions are governed by the magnitude of δΔH ≠ int. Copyright © 2011 John Wiley & Sons, Ltd.

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