S 98 Synthesis of 4-amino derivatives of 5-oxoproline [Text] / V. P. Krasnov, A. Yu. Vigorov, I. A. Nizova, T. V. Matveeva, A. N. Grishakov, I. V. Bazhov, A. A. Tumashov, M. A. Ezhikova, M. I. Kodess // European Journal of Organic Chemistry. - 2007. - № 25. - P4257-4266 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The possibility of obtaining the stereoisomeric derivatives of 5-oxoproline and glutamic acid with a tertiary amino group at C-4, using the nucleophilic substitution of bromine in dimethyl (2S,4RS)-4-bromo-N-phthaloylglutamate with secondary amines followed by resolution of diastereomers and removal of protecting groups has been studied. We have shown that the reaction with arylamines results in optically pure 5-oxoproline derivatives in high yields. In the case of more basic amines, the reaction is accompanied by racemization, and the target products can be isolated only as diastereomeric racemates. |
D 62 Direct diastereoselective addition of l-menthol to activated 1,2,4-triazin-5(4H)-one [Text] / O. N. Chupakhin, G. V. Zyryanov, V. L. Rusinov, V. P. Krasnov, G. L. Levit, M. A. Koroleva, M. I. Kodess // Tetrahedron Letters. - 2001. - Vol. 42, № 12. - P2393-2395 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: For the first time in a triazine series it has been found that addition of a chiral O-nucleophile, l-menthol, to the C6-unsubstituted atom of 3-phenyl-1,2,4-triazin-5(4H)-one 1 activated by aliphatic acid anhydrides proceeds diastereoselectively to form a mixture of 1-acyl-6-[(1?R,3?R,4?S)-menthyl-3?)]-3-phenyl-(6S)-1,6-dihydro-1,2,4-triazin-5(4H)-ones 2 and 1-acyl-6-[(1?R,3?R,4?S)-menthyl-3?)]-3-phenyl-(6R)-1,6-dihydro-1,2,4-triazin-5(4H)-ones 3 in which the diastereomers 2 predominate. The diastereoselectivity of the process improves as the size of the N1-acyl substituent increases???? |
F 94 From oxides of internal perfluoroolefins to fluorocontaining camphor thiazolinylhydrazones [Text] / L. V. Saloutina, A. Ya. Zapevalov, M. I. Kodess, K. A. Lyssenko, M. Yu. Antipin, V. I. Saloutin, O. N. Chupakhin // Journal of Fluorine Chemistry. - 2003. - Vol. 120, № 1. - P41-47 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The reaction of oxides of internal trans- and cis-perfluoroolefins with (1S, 4S)- or racemic camphor thiosemicarbazone leads to the formation of trans- and cis-isomers of (1S, 4S)- or racemic camphor 5?-fluoro-4?-hydroxy-4?,5?-di(perfluoroalkyl)-1?,3?-thiazolinyl-2?-hydrazones, respectively. Unsymmetrical dodecafluoro-2,3-epoxyhexane yields a mixture of regioisomeric hydrazones. The molecular structure of the trans-isomer of (1S, 4S)-camphor 5?-fluoro-4?-hydroxy-4?,5?-bis(trifluoromethyl)-1?,3?-thiazolinyl-2?-hydrazone has been established by X-ray crystallography. The quite rare example of cocrystallization of two diastereomers of the latter in homochiral crystal (sp. group P21) has been revealed???? |
R 30 Reactions of 3-nitro-2-trihalomethyl-2H-chromenes with S-and N-nucleophiles. Synthesis and stereochemistry of 2,3,4-trisubstituted chromanes [Electronic resource] / V. Yu. Korotaev, V. Ya. Sosnovskikh, I. B. Kutyashev, M. I. Kodess // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2006. - Vol. 55, № 2. - P317-330 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The reactions of 3-nitro-2-trifluoromethyl-and 3-nitro-2-trichloromethyl-2H-chromenes with thiols and aromatic amines proceed via the nucleophilic addition type to the activated double bond to form 2,3,4-trisubstituted chromanes in high yields. The stereoisomeric compositions and structures of the diastereomers were determined by 1H, 19F NMR and 2D NOESY spectroscopies and X-ray diffraction analysis \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2006, 55 (2), 317.pdf |
K 81 Krasnov, V. P. Nucleophilic substitution of halogen in 4-halo derivatives of glutamic acid 3. High pressure effect on the stereochemical result of the reaction [Electronic resource] / V. P. Krasnov, M. A. Koroleva, G. L. Rusinov // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 1996. - Vol. 45, № 3. - P543-544 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Reactions of diastereomeric dialkyl N-phthaloyl-4-haloglutamates withpara-anisidine were studied at high pressure, and an additional confirmation of the exactS N2 mechanism of the reactions was obtained. Quantitative parameters of the relative reactivity of the diastereomers were found in various solvents, which made it possible to perform the desired synthesis of products of diastereomeric substitution. kg]Key words kw]glutamic acid kw]diastereoselectivity kw]nucleophilic substitution kw]reaction rate constant kw]high pressure. \\\\Expert2\\nbo\\Russian Chemical Bulletin\\1996, 45 (3), 543.pdf |
K 81 Krasnov, V. P. Nucleophilic-substitution of halogen in 4-halogenated derivatives of glutamic-acid. 1. Solvent effect [Electronic resource] / V. P. Krasnov, M. A. Koroleva // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 1995. - Vol. 44, № 4. - P631-634 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): GLUTAMIC ACID -- DIASTEREOSELECTIVITY -- NUCLEOPHILIC SUBSTITUTION -- RATE CONSTANT -- SOLVENT EFFECT Аннотация: The reaction of nucleophilic substitution of bromine by p-anisidine in dimethyl (2S,4S)- and (2S,4R)-N-phthaloyl-4-bromoglutamates proceeds according to the S(N)2 mechanism. The relative reactivity of diastereomers in various solvents was studied. \\\\Expert2\\nbo\\Russian Chemical Bulletin\\1995, 44 (4), 631.pdf |
N 91 Nucleophilic-substitution of halogen in 4-halogenated derivatives of glutamic-acid. 2. Structural effects of arylamine as nucleophile [Electronic resource] / V. P. Krasnov, M. A. Koroleva, N. G. Evstigneeva, I. A. Nizova // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 1995. - Vol. 44, № 4. - P635-638 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): GLUTAMIC ACID -- DIASTEREOSELECTIVITY -- NUCLEOPHILIC SUBSTITUTION -- RATE CONSTANT -- ARYLAMINE Аннотация: Kinetics of nucleophilic substitution of halogen in diastereomeric dimethyl 4-bromo- and 4-iodoglutamates with ortho-, meta-, and para-substituted anilines was studied by HPLC. The threo-diastereomers of the halogenated derivatives react 3-5 times faster than the erythro ones. The structure of the transition state is discussed. \\\\Expert2\\nbo\\Russian Chemical Bulletin\\1995, 44 (4), 635.pdf |
R 30 Reaction of alkyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylates with zinc enolates prepared from zinc and 1-arul-2-bromo-2-phenylethanones, 2 bromoindanone, and 2-bromo-6-methyltetralone [Electronic resource] / V. V. Shchepin, A. E. Korzun, M. I. Vakhrin, P. S. Silaichev, M. A. Ezhikova, M. I. Kodess // Russian Journal of Organic Chemistry (Translation of Zhurnal Organicheskoi Khimii). - 2006. - Vol. 42, № 8. - P1169-1173 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Alkyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylates react with zinc enolates prepared from 1-aryl-2-bromo-2-phenylethanones, 2-bromo indanone, 2-bromo-6-methyltetralone and zinc with formation of ethyl 4-(2-aryl-2-oxo-1-phenyl-ethyl)-5,5-dimethyl-2-oxotetrahydrofuran-3-carboxylates, alkyl 5,5-dimethyl-2-oxo-4-(1-oxoindan-2-yl)tetrahydrofuran-3-carboxylates, and ethyl 5,5-dimethyl-4-(6-methyl-1-oxo-1,2,3,4-tetrahydronaphthalen-2-yl)-2-oxotetrahydrofuran-3-carboxylates respectively, mainly as single diastereomers \\\\Expert2\\nbo\\Russian Journal of Organic Chemistry\\2006, 42 (8), 1169.pdf |
A 10 A simple synthesis of the pentacyclic lamellarin skeleton from 3-nitro-2-(trifluoromethyl)-2H-chromenes and 1-methyl(benzyl)-3,4-dihydroisoquinolines / V. Yu. Korotaev, V. Ya. Sosnovskikh, A. Yu. Barkov, P. A. Slepukhin, M. A. Ezhikova, M. I. Kodess, Yu. V. Shklyaev // Tetrahedron. - 2011. - Vol. 67, № 45. - С. 8685-8698 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): LAMELLARIN ALKALOIDS -- ISOQUINOLINE DERIVATIVES -- HETEROCYCLIC SYSTEM Аннотация: The basic structural framework of lamellarin alkaloids, 8,9-dihydro-6H-chromeno[4?,3?:4,5]pyrrolo[2,1-a]isoquinoline derivatives, has been obtained in good yields via Grob synthesis between 3-nitro-2-(trifluoromethyl)-2H-chromenes and 1-methyl-3,4-dihydroisoquinolines in refluxing isobutanol. In the case of 1-benzyl-3,4-dihydroisoquinolines, a dynamic NMR effect was observed in the 1H and 19F NMR spectra of the products as a result of restricted rotation about the single bond linking the benzene ring and the heterocyclic system. When the reaction was carried out with 3-nitro-2-(trichloromethyl)-2H-chromenes in toluene at room temperature, only Michael adducts, as a mixture of two diastereomers, were isolated.??????--------------------------------------------------------------------------------?? |
R 35 Regioselective reaction of ortho-piperidinobenzaldehydes with pyrazolone [Electronic resource] / A. Yu. Platonova, E. V. Deeva, O. A. Zimovets, D. V. Shatunova, O. S. Eltsov, P. A. Slepukhin, T. V. Gluchareva, Yu. Yu. Morzherin // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2011. - Vol.60, №5. - С. 961-964. - Bibliogr. : p. 964 (20 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): TERT-AMINO EFFECT -- PYRAZOLONE -- DIASTEREOMERS Аннотация: Cyclization of 2 (4 R piperidino)benzaldehydes with 5 methyl 2 phenyl 2,4 dihydro 3H pyrazol 3 one proceeding via tert amino effect mechanism is stereoselective. Relative configu ration of (3R*,4aS*,5R*) 2,3,4,4a,5,6 hexahydro 1H benzo[c]quinolizine was established on the base of NMR spectroscopy data and X ray analysis \\\\expert2\\NBO\\Russian Chemical Bulletin\\2011, 60 (5), 961-964.pdf |
2-Arylpropionyl chlorides in kinetic resolution of racemic 3-methyl-2,3-dihydro-4H-[1,4]benzoxazines [Electronic resource] / E. N. Chulakov, D. A. Gruzdev, G. L. Levit, L. Sh. Sadretdinova, V. P. Krasnov, V. N. Charushin // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2011. - Vol.60, №5. - С. 948-954. - Bibliogr. : p. 953-954 (34 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): KINETIC RESOLUTION -- ACYL CHLORIDES -- ENANTIOMERS Аннотация: Kinetic resolution of racemic 3 methyl 2,3 dihydro 4H [1,4]benzoxazines in the reaction with chiral 2 arylpropionyl chloride predominantly yielded R*,R* diastereomers. Ibuprofen acyl chloride as acylating agent was found to be more selective and sensitive to the changes in the reaction temperature as compared to naproxen acyl chloride and 2 phenylpropionyl chloride \\\\expert2\\NBO\\Russian Chemical Bulletin\\2011, 60 (5), 948-954.pdf |
S 83 Stereochemical aspects in the synthesis of novel N-(purin-6-yl)dipeptides as potential antimycobacterial agents / V. V. Musiyak, I. A. Nizova, E. N. Chulakov [et al.] // Amino Acids. - 2021. - Vol. 53, № 3. - P407-415 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): DIPEPTIDES -- RACEMIZATION -- PURINE -- COUPLING -- NUCLEOPHILIC SUBSTITUTION -- ANTIMYCOBACTERIAL ACTIVITY Аннотация: The synthesis of purine conjugates with natural amino acids is one of the promising directions in search for novel therapeutic agents, including antimycobacterial agents. The purpose of this study was to synthesize N-(purin-6-yl)dipeptides containing the terminal fragment of (S)-glutamic acid. To obtain the target compounds, two synthetic routes were tested. The first of them is based on coupling of N-(purin-6-yl)-(S)-amino acids to dimethyl (S)-glutamate in the presence of carbodiimide coupling agent followed by the removal of ester groups. However, it turned out that this coupling process was accompanied by racemization of the chiral center of N-(purin-6-yl)-α-amino acids and in all cases led to mixtures of (S,S)- and (R,S)diastereomers (6:4). Individual (S,S)-diastereomers were obtained using an alternative approach based on the nucleophilic substitution of chlorine in 6-chloropurine or 2-amino-6-chloropurine with corresponding dipeptides as nucleophiles. The enantiomeric purity of the target compounds was confirmed by chiral HPLC. To test the assumption that racemization of the chiral center of N-(purin-6-yl)-α-amino acids occurs with the participation of nitrogen atoms of the imidazole ring via the stage of formation of a chirally labile intermediate, we obtained such structural analogs of N-(purin-6-yl)-(S)-alanine as N-(9-benzylpurin-6-yl)-(S)-alanine and N-(7-deazapurin-6-yl)-(S)-alanine. It was found that coupling of these compounds to dimethyl (S)-glutamate was also accompanied by racemization. This indicates that the imidazole fragment does not play a crucial role in this process. When testing the antimycobacterial activity of some of the obtained compounds, conjugates with moderate activity against the laboratory Mycobacterium tuberculosis H37Rv strain (MIC 3.1–6.25 μg/mL) were identified. |
Synthesis of heterocycles on the base of trifluoroacetoacetate, methyl ketones and diamines / M. V. Goryaeva, S. O. Kushch, Y. V. Burgart, V. I. Saloutin // AIP conference proceedings. - 2022. - Vol. 2390. - Ст. 020021 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): TRIFLUOROACETOACETATE -- METHYL KETONES -- DIAMINES Аннотация: The three-component cyclization of ethyl trifluoroacetoacetate and 2-aminoethanol with 3-methyl-2-butanone in hexahydrooxazolo[3,2-a]pyridin-5-ones was studied. The reaction leads to a mixture of cis- and trans- diastereomers, the structures of which were investigated using 1H, 19F, 13C NMR spectroscopy. |
Korolyova, M. A. Theoretical study of the stereoselectivity in the reaction of 4-haloglutamic acid derivatives with arylamines / M. A. Korolyova, A. Yu. Vigorov, V. P. Krasnov // Russian chemical bulletin. - 2022. - Vol. 71, № 6. - P1135-1142 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Diastereoselective nucleophilic substitution reaction of halogen in dimethyl (2S,4RS)-4-bromo- and 4-iodo-N-phthaloylglutamates with arylamines was studied within the framework of the electron density functional theory. According to calculations, the stereoselectivity of the substitution reaction with respect to (2S,4S)-isomers of 4-arylamino derivatives is determined not only by the steric hindrances in the transition state leading to minor (2S,4R)-diastereomers, but also by the stabilization of the corresponding initial reagents complex due to stacking interactions of the aromatic fragments of reagents. |