S 98 Synthesis of fluoroalkylated dihydroazolo[1,5-a]pyrimidines and their ring-chain isomerism [Text] / M. V. Goryaeva, Ya. V. Burgart, V. I. Saloutin, E. V. Sadchikova, E. N. Ulomskii // Heterocycles. - 2009. - Vol. 78, № 2. - P435-447 : рис. - Bibliogr. : p. 446-447 (11 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ |
B 96 Burgart, Ya. V. Ring-chain isomerism of 7-Fluoroalkyl-4,7-dihydroazolo[1,5-a]pyrimidines [Text] : доклад, тезисы доклада / Ya. V. Burgart, M. V. Pryadeina, V. I. Saloutin // 15th European symposium on fluorine chemistry, Prague, Czech Republic, July 15-20, 2007 : abstr. - 2007. - P192 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): 7-FlUOROALKYL-4,7-DIHYDROAZOLO[1,5-A]PYRIMIDINES -- RING-CHAIN ISOMERISM |
G 37 Geometric isomerism in the series of fluoroalkyl-containing 1,2,3-trione 2-arylhydrazones [Electronic resource] / O. G. Khudina, E. V. Shchegol'kov, M. I. Kodess, Ya. V. Burgart, V. I. Saloutin, O. N. Chupakhin // Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii). - 2007. - Vol. 43, № 3. - P380-387 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): 2-ARYLHYDRAZONES -- X-RAY DIFFRACTION Аннотация: According to the 1H, 13C, and 19F NMR data, fluoroalkyl-containing 1,2,3-trione 2-arylhydrazones in CDCl3 exist exclusively, while in (CD3)2CO preferentially, as isomers in which the acyl or aroyl group is involved in intramolecular hydrogen bond. The isomer structure was assigned on the basis of the chemical shifts of the carbonyl carbon atoms and fluorine atoms and carbon-fluorine spin-spin coupling constants J C-F. X-Ray diffraction data showed that 1,2,3-trione 2-arylhydrazones in crystal have the same structure as in CDCl3 solution. Quantum-chemical calculations were performed to rationalize predominant formation of 1,2,3-trione 2-arylhydrazone isomers with a free polyfluoroacyl group \\\\Expert2\\nbo\\Russian Journal of Organic Chemistry\\2007, 43 (3), 380-387.pdf |
R 59 Ring-chain isomerism of ethyl 7-polyfluoroalkyl-7-hydroxy-4,7-dihydro[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylates [] / M. V. Pryadeina, Ya. V. Burgart, V. I. Saloutin, O. N. Chupakhin // Mendeleev Communications. - 2008. - Vol. 18, № 5. - С. 276-277. - Bibliogr. : p.277 (10 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Cyclisation of ethyl 2-ethoxymethylidene-3-oxo-3-polyfluoroalkylpropionates with 3-amino-1H-[1,2,4]triazole gives ethyl 7-polyfluoroalkyl-7-hydroxy-4,7-dihydro[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylates that are subject to ring–chain isomerisation in solution, depending on the solvent and the length of the polyfluoroalkyl substituent, to yield ethyl 3-polyfluoroalkyl-3-oxo-2-{([1,2,4]triazol-3-yl)aminomethylidene}propionates via heterocyclic ring opening at the C(7)–N(8) bond \\\\Expert2\\nbo\\Mendeleev Communications\\2008, v.18, p.276.pdf |
A 37 Alkyl 3-fluoroalkyl-3-oxopropionates in reactions with azolyldiazonium salts [Electronic resource] / E. V. Shchegol'kov, E. V. Sadchikova, Ya. V. Burgart, V. I. Saloutin // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2008. - Vol. 57, № 3. - P612-618 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Alkyl 3-fluoroalkyl-3-oxopropionates react with antipyrinyldiazonium chloride to form 2-antipyrinylhydrazono-3-fluoroalkyl-3-oxopropionates. The use in these reactions of hetaryldiazonium salts, containing NH group in the ? position, leads to alkyl 7-fluoroalkyl-7-hydroxy-4,7- dihydroazolo[5,1-c]triazine-6-carboxylates. 3-Amino-1H-1,2,4-triazole, 3-amino-4-ethoxycar- bonyl-1H-pyrazole, and 5-amino-4-ethoxycarbonyl-1H-imidazole were used as the heterocyclic component \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2008, 57 (3), 612.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 |
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 |
A 10 A convenient approach to 4,7-dihydrotetrazolo [5,1-c ][1,2,4]triazine synthesis [Electronic resource] / E. V. Shchegol'kov, A. E. Ivanova, Ya. V. Burgart, V. I. Saloutin // Journal of Heterocyclic Chemistry. - 2013. - Vol.50. - PE80-E86 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): TRIAZINE SYNTHESIS -- 1,3-DICARBONYL -- ISOMERISM Аннотация: Azo coupling of 1,3-dicarbonyl compounds with tetrazolyl-5-diazonium chloride is used to develop a convenient one-step procedure for the synthesis of 4,7-dihydrotetrazolo[5,1-c][1,2,4]triazines. In contrast to nonfluorinated analogs, 7-hydroxy-7-polyfluoroalkyl-4,7-dihydrotetrazolo[5,1-c][1,2,4]triazines undergo a ring-chain isomerism resulting from the cleavage at the C7 - N7a bond. A distinctive feature of nonfluorinated 4,7-dihydrotetrazolo[5,1-c][1,2,4] triazines is the possibility to dehydration, which is accompanied by an azide rearrangement due to the tetrazole ring cleavage with the formation of tetrazolo[1,5-b][1,2,4]triazines |