F 70 Fluoroalkyl-containing beta,beta-tricarbonyl compounds - tautomerism and reaction with N-nucleophiles [Electronic resource] / V. M. Krokhalev, V. I. Saloutin, A. D. Romas, B. A. Ershov, K. I. Pashkevich // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 1990. - Vol. 39, N 2. - P316-322 Рубрики: ХИМИЧЕСКИЕ НАУКИ \\\\Expert2\\nbo\\Russian Chemical Bulletin\\1990, 39 (2), 316.pdf |
5(6)-Fluoro-6(5)-R-benzofuroxans: synthesis and NMR 1H, 13C and 19F studies [Text] / S. K. Kotovskaya, S. A. Romanova, V. N. Charushin, M. I. Kodess, O. N. Chupakhin // Journal of Fluorine Chemistry. - 2004. - Vol. 125, № 3. - P421-428 : ил. - Библиогр.: с. 428 (14 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): 5,6-DIFLUOROBENZOFUROXAN -- NUCLEOPHILIC SUBSTITUTION -- X-RAY CRYSTALLOGRAPHY Аннотация: 5(6)-Fluoro-6(5)-substituted benzofuroxans were obtained by the reactions of 5,6-difluorobenzofuroxan with a number of nucleophiles, such as alkylamines, cycloalkylimines, sodium azide and sodium alkoxides. The features of tautomerism in the series of asymmetrical 5(6)-fluorobenzofuroxans in acetone solutions have been studied by 1H, 13C and 19F NMR.???? \\\\Expert2\\nbo\\Journal of Fluorine Chemistry\\2004, v.125, p.421.pdf |
S 98 Synthesis and Tautomeric Equilibrium of Polyfluoroacyl-Containing 1,5-Benzodiazepines [Text] / D. S. Yachevskii, D. L. Chizhov, M. I. Kodess, K. I. Pashkevich // Monatshefte fur Chemie . - 2004. - Vol. 135, № 1. - P23-30 : ил. - Библиогр.: с. 30 (8 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): NMR -- TAUTOMERISM -- SYNTHESIS Аннотация: The reaction of bis(polyfluoroalkyl)-containing 1,3,5-triketones with o-phenylenediamine yielded 2-polyfluoroacylmethylene-4-polyfluoroalkyl-1,3- or 1,5-dihydro-1,5-benzodiazepines. The tautomeric equilibrium of the obtained benzodiazepines in CDCl3, CD3CN, DMSO, and DMF solution was studied.?? |
F 26 Fast Enol-enol Tautomerism of Fluorinated 1,3-Dicarbonyl and 1,3.5-Tricarbonyl Compounds Reinvestigated [Text] : доклад, тезисы доклада / D. V. Sevenard, G. -V. Roeschenthaler, I. I. Bilkis, M. I. Kodess, D. L. Chizhov, K. I. Pashkevich, D. V. Sevenard // 18th ISFC international Symposium on Fluorine Chemistry. Bremen, 30th Jul.-4 Aug. 2006 г. : Final Program. Abstracts. - Bremen, 2006. - P180 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ENOL-ENOL -- TAUTOMERISM -- TRICARBONY |
S 98 Synthesis and structure of 4-hydroxy-4-fluoroalkyl-1,4-dihydroimidazo[5,1-c][1,2,4]triazines [Electronic resource] / E. V. Shchegol'kov, E. V. Sadchikova, Ya. V. Burgart, V. I. Saloutin // Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii). - 2009. - Vol. 45, № 4. - P572-580 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Azo coupling of fluorinated 1,3-diketones with 4-ethoxycarbonyl-1H-imidazole-5-diazonium chloride led to the formation of 4-hydroxy-4-polyfluoroalkyl-1,4-dihydroimidazo[5,1-c][1,2,4]triazines. According to the 1H and 19F NMR data, these compounds in solution give rise to ring-chain tautomerism via opening of the C4-N5 bond, which is especially characteristic of dihydroimidazotriazines with a polyfluoroalkyl substituent longer than trifluoromethyl group \\\\Expert2\\nbo\\Russian Journal of Organic Chemistry\\2009, 45 (4), 572.pdf |
F 70 Fluorine-containing Heterocycles. XI. 5(6)-Fluoro-6(5)-X-benzofuroxans: Synthesis, Tautomerism, and Transformations [Electronic resource] / O. N. Chupakhin, S. K. Kotovskaya, S. A. Romanova, V. N. Charushin // Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii). - 2004. - Vol. 40, № 8. - P1167-1174 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Features of 5(6)-fluoro-6(5)-X-benzofuroxans tautomerism were investigated. By 1H, 13C, and 19F NMR spectroscopy the direction of Boulton-Katritzky rearrangement in nitration, nitrosation, and azo coupling of fluorine-containing furoxanes was determined \\\\Expert2\\nbo\\Russian Journal of Organic Chemistry\\2004, 40 (8), 1167.pdf |
I-85 Isomerism and tautomerism of 5-fluoroalkyl-substituted 3-acetyldihydrofuran-2(3H)-ones [Electronic resource] / M. I. Kodess, E. G. Matochkina, D. N. Bazhin, T. I. Gorbunova, A. Ya. Zapevalov // Russian Journal of General Chemistry. - 2009. - Vol. 79, № 4. - P800-807 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The geometric isomerism and tautomeric equilibrium of 5-fluoroalkyl-3-acetyldihydrofuran-2(3H)-ones obtained by condensation of (perfluoroalkyl)methyloxiranes with acetoacetic ester were studied. In the solid state the acyl-?-lactones are in diketo form, mainly as cis isomer, whose structure is confirmed by the data of X-ray structural investigation, while in solution an equilibrium exists of cis-trans isomers and an enol form, as established by 1D and 2D methods of 1H, 13C, and 19F NMR spectroscopy \\\\Expert2\\nbo\\Russian Journal of General Chemistry\\2009, V. 79, N 4, p.800.pdf |
S 69 S-N(H)-Reactions of triazolo[4,3-b]- and tetrazolo[1,5-b]-1,2,4-triazines with methylene-active carbonyl compounds [Electronic resource] / G. L. Rusinov, N. A. Itsikson, D. G. Beresnev, M. I. Kodess, O. N. Chupakhin // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2001. - Vol. 50, № 11. - P2183-2187 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Unsubstituted triazolo[4,3-b]- and tetrazolo[1,5-b]-1,2,4-triazines react with carbanions generated from dimedone and barbituric acid to give adducts of a C-nucleophile with the heterocyclic system through the C=N double bond. The adducts can be oxidized under mild conditions into products of nucleophilic hydrogen substitution. Analogous adducts with carbanions produced in the reactions of ethyl cyanoacetate and ethyl malonate with ButOK proved to be unstable; in this case, the title azolotriazines immediately yield products of nucleophilic hydrogen substitution in position 7. Tautomerism of the S N H products obtained is discussed. \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2001, 50 (11), 2183.pdf |
S 98 Synthesis, Structure, and Keto-Enol Tautomerism of 3-R1-5,5-R2,R2-6-R3-2,3,5,6-Tetrahydropyran-2,4-diones [Electronic resource] / V. V. Shchepin, M. I. Kodess, Yu. Kh. Sazhneva, N. Yu. Russkikh // Russian Journal of General Chemistry. - 2005. - Vol. 75, № 10. - P1622-1627 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Ethyl esters of 2,4-dibromo-2-R1-4-R2-3-oxopentanoic and -hexanoic acids react with zinc and aliphatic or aromatic aldehydes under the conditions of the Reformatskii reaction to give 3-R1-5,5-R2, R2-6-R3-2,3,5,6-tetrahydropyran-2,4-diones, which are obtained in three forms: keto, enol with enolization of the keto group, and enol with enolization of the ester group. The keto form is isolated by crystallization from a mixture of CCl4 and petroleum ether; the first enol form, from MeOH, EtOH, and polar aprotic solvents; and the second enol form, from CHCl3. The second enol form is oxidized in DMSO to form a keto compound containing a hydroxy group at the 3-position of the heteroring \\\\Expert2\\nbo\\Russian Journal of General Chemistry\\2005, V. 75, N 10, p.1622.pdf |
A 18 Acid-base properties and prototropic tautomerism of isomeric 1,2,4-triazin-3- and -5-ones [Electronic resource] / I. V. Khabibulina, R. E. Trifonov, A.P. Volovodenko, M. S. Eremenkova, O. N. Chupakhin, V. L. Rusinov, G. V. Zyryanov, V. A. Ostrovskii // Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii). - 2004. - Vol. 40, № 3. - P426-430. - Bibliogr. : p. 430 (40 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ACID -- BASE -- TRIAZINE DERIVATIVE -- AQUEOUS SOLUTION Аннотация: The acidity and basicity constants of isomeric phenyl(aryl)-1,2,4-triazin- 3- and -5-ones in aqueous solution were determined by spectrophotometry: pK a = 7.3-6.2; pKBH+ = 0.1 to -2.2. 1,2,4-Triazin-3-ones are weaker bases than the corresponding 1,2,4-triazin-5-ones. According to the AM1 calculations, the most thermodynamically favorable tautomer in the gas phase is the oxo form: namely, 2H-tautomers of the neutral bases and 2,4-H,H +-tautomers of the conjugate acids. \\\\Expert2\\nbo\\Russian Journal of Organic Chemistry\\2004, 40 (3), 426.pdf |
(Het)aroylpyruvic acids and their derivatives as promising building blocks for organic synthesis [Electronic resource] / S. G. Perevalov, Ya. V. Burgart, V. I. Saloutin, O. N. Chupakhin // Russian Chemical Reviews. - 2001. - Vol. 70, № 11. - P921-938. - Bibliogr. : p. 938 (191 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Methods of synthesis of (het)aroylpyruvic acids and their acyclic derivatives (esters, amides and hydrazides), and their reactions with various C-, N-, O-, S-nucleophiles are described. Problems of tautomerism and biological activity of (het)aroylpyruvates and products of their transformation are briefly considered |
U 62 Unusual ring-chain tautomerism in bicyclo[4.2.0]octane derivatives [Text] / V. Yu. Korotaev, A. Yu. Barkov, P. A. Slepukhin, M. I. Kodess, V. Ya. Sosnovskikh // Tetrahedron Letters. - 2011. - Vol. 52, № 23. - P3029-3032 : рис. Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: A new type of ring-chain tautomerism, which consists of the reversible conversion of bicyclo[4.2.0]octane derivatives into trisubstituted enamines was found and studied by 1H NMR spectroscopy. The starting materials were prepared by the stereoselective reaction of (E)-3,3,3-trichloro-1-nitropropene with cyclohexanone enamines \\\\Expert2\\nbo\\Tetrahedron Letters\\2011, v. 52, p. 3029.pdf |
U 50 Uncatalyzed reactions of alfa-(trihaloethylidene)nitroalkanes with push-pull enamines: a new type of ring-ring tautomerism in cyclobutane derivatives and the dramatic effect of the trihalomethyl group on the reaction pathway [Text] / V. Yu. Korotaev, A. Yu. Barkov, P. A. Slepukhin, M. I. Kodess, V. Ya. Sosnovskikh // Tetrahedron Letters. - 2011. - In Press, Accepted Manuscript, 30 august 2011. - P1-15. - Bibliogr. : p. 10-12 (15 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: A new type of ring-ring isomerism, which consists of the reversible transformation of cyclobutane derivatives into substituted 1,2-oxazine N-oxides was found and studied by NMR spectroscopy and X-ray diffraction analysis. The starting materials were prepared by the stereoselective reaction of ?-(trifluoroethylidene)nitroalkanes, which react with ethyl ?-morpholino- and ?-piperidinocrotonates at the more nucleophilic ?-position, whereas the reaction of ?-(trichloroethylidene)nitroalkanes proceeds at the ?-methyl group to give the corresponding linear products \\\\Expert2\\nbo\\Tetrahedron Letters\\2011, In Press, Acc. Man. 30 aug.pdf |
S 89 Structure of diethyl (polyfluorobenzoyl)malonates and their thermal intramolecular cyclizat / D. N. Bazhin, E. V. Schegolkov, Yu. S. Kudyakova, Ya. V. Burgart, V. I. Saloutin // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2011. - Vol.60, №5. - С. 929-932 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): POLYFLUOROBENZOYL -- POLYFLUOROBENZOYL CHLORIDES -- CYCLIZATION Аннотация: The reaction of the C-ethoxymagnesium derivative of diethyl malonate with polyfluorobenzoyl chlorides affords the corresponding (polyfluorobenzoyl)malonates prone to thermal cyclization into coumarin derivatives. The compounds obtained are inherent in keto—enol tautomerism \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2011, 60 (5), 929-932.pdf |
S 89 Structure of 5,6,7,8-tetrafluoro-4-hydroxycoumarins [Электронный ресурс] / K. V. Scherbakov, Ya. V. Burgart, M. I. Kodess, V. I. Saloutin // Chemistry of Heterocyclic Compounds. - 2012. - Vol.48, №9. - P1297-1306 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): 5,6,7,8-TETRAFLUORO-4-HYDROXYCOUMARIN -- IMINE-ENAMINE TAUTOMERISM -- KETO-ENOL TAUTOMERISM Аннотация: The structure of 5,6,7,8-tetrafluoro-4-hydroxycoumarin and its 3-substituted derivatives was studied by X-ray structural analysis and IR, 1H, 13C, and 15N NMR spectroscopy. It was established that the nature of the substituent at the position 3 of the coumarin ring has a significant effect on its stru \\\\Expert2\\NBO\\Chemistry of Heterocyclic Compounds\\2012, v.48, N 9, p.1297-1306.pdf |
2-Azido-5-nitropyrimidine: Synthesis, Molecular Structure, and Reactions with N-, O-, and S-Nucleophiles [Electronic resource] / E. B. Gorbunov, R. K. Novikova, P. V. Plekhanov, P. A. Slepukhin, G. L. Rusinov, V. L. Rusinov, V. N. Charushin, O. N. Chupakhin // Chemistry of Heterocyclic Compounds. - 2013. - Vol.49, №5. - P765-775. - Библиогр.: с. 775 (13 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): SYNTHESIS -- 2-AZIDO-5-NITROPYRIMIDINE -- AZIDO-TETRAZOLE TAUTOMERISM Аннотация: We describe the synthesis of 2-azido-5-nitropyrimidine and its azido-tetrazole tautomerism in various solvents and in the crystalline state. It was established that on interacting with N-nucleophiles the attack occurred at the C-2 carbon atom. The O- and S-nucleophiles attacked C-4 position of pyrimidine ring, resulting in tetrazole ring closure \\\\expert2\\NBO\\Chemistry of Heterocyclic Compounds\\2013, v.49, N 5, p. 765-775.pdf |
S 78 Spin-spin coupling constants 13C-15N and 1H-15N in the investigation of azido-tetrazole tautomerism in a series of 2-azidopyrimidines [Electronic resource] / I. A. Khalymbadzha, T. S. Sheshukova, S. L. Deev , V. L. Rusinov, O. N. Chupakhin, Z. O. Shenkarev, A. S. Arseniev // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2013. - Vol.62, №2. - С. 521-528. - Bibliogr. : p. 528 (25 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): AZIDO-TETRAZOLE EQUILIBRIUM -- SPIN-SPIN COUPLING -- 2-AZIDOPYRIMIDINES Аннотация: A new method was developed for the investigation of an azido-tetrazole equilibrium based on using a complex analysis of 13C-15N and 1H-15N spin-spin coupling constants. The use of this approach became possible due to the selective inclusion of 15N isotopes into the structures of 2-azidopyrimidines and their cyclic analogs tetrazolo[1,5-a]pyrimidines \\\\expert2\\nbo\\Russian Chemical Bulletin\\2013, 62 (2), 521-528.pdf |
S 98 Synthesis of new 5-aza-isosteres of guanine—5-aminosubstituted 1,2,4-triazolo[1,5-a]-1,3,5-triazin-7-ones [Electronic resource] / V. V. Bakharev, V. E. Parfenov, I. V. Ulyankina, A. V. Zavodskskaya, E. V. Selezneva, A. A. Gidaspov, O. S. Eltsov, P. A. Slepukhin // Tetrahedron. - 2014. - Vol. 70, № 38. - С. 6825-6830 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): FUSED-RING SYSTEMS -- REARRANGEMENT -- TAUTOMERISM Аннотация: The reaction of 4-amino-substituted 6-hydrazinyl-1,3,5-triazin-2(1H)-ones with orthoformate proceeds via the Dimroth-type rearrangement to give 5-amino-substituted 1,2,4-triazolo[1,5-a]-1,3,5-triazine-7-ones. IR, NMR and X-ray studies have shown that the only product of the reaction was the [1,5-a]-isomer as prototropic 3H- and 6H-tautomers. \\\\expert2\\nbo\\Tetrahedron\\2014, v. 70 (38), p. 6825.pdf |
C 91 Crystal structure, spectral and thermal properties of 1,2-bis[2-(4,4,4-trifluoro-1-hydroxy-3-oxobut-1-enyl)phenoxy]-ethane and luminescent properties of its complexes with Al(III) and Eu(III) [Electronic resource] / L. A. Khamidullina, K. L. Obydennov, P. A. Slepukhin, I. S. Puzyrev // Journal of Molecular Structure. - 2016. - Vol. 1125. - С. 550-557 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): LANTHANIDE COMPLEXES -- ENOL-TAUTOMERISM -- BETA-DIKETONES Аннотация: Describing the crystal structure, packing, FT-IR, UV-Vis and NMR spectra and thermal properties of new polydentate O-ligand based on aryl-beta-diketone moieties connected by ethylene glycol spacer is the subject of this article. The results of IR, UV-Vis and H-1 NMR spectroscopy as well X-ray crystallography of 1,2-bis[2-(4,4,4-trifluoro-1-hydroxy-3-oxobut-1-enyl)phenoxy]-ethane (BTFPE) indicate that the compound exists in solution and in solid as enol. The crystal structure analysis shows that BTFPE has C2/c group of the monoclinic system. Typical S(6) intramolecular hydrogen bond occurs in each 1,3-diketo moiety. This bond is asymmetric and the H atom is closest to the 0 atom adjacent to the phenyl ring. The packing of the crystal is sustained by numerous C-H center dot center dot center dot O, O-H center dot center dot center dot F, C-H center dot center dot center dot F interactions. In the crystal, supramolecular zig-zag chains are formed along the c-axis. Short contacts interconnect the molecules into a two-dimensional layered structure wherein each molecule is node between chains. According to the thermal investigation this compound is stable up to 200 degrees C in air atmosphere, above this temperature it decomposes. Photoluminescent properties of aluminum(III) and europium(III) complexes of BTFPE were evaluated in chloroform solution and in the solid state. Aluminum complex of BTFPE shows blue luminescence with maximum at 445 nm. Europium complex exhibits intense red color luminescence at 613 nm from central Eu(III) ion through the excitation of the ligand. \\\\expert2\\NBO\\Journal of Molecular Structure\\2016, v.1125, p.550-557.pdf |