N 10 N-Phthaloyl-(S)-alanyl chloride as a chiral resolving agent for the kinetic resolution of heterocyclic amines [Text] / V. P. Krasnov, G. L. Levit, M. I. Kodess, V. N. Charushin, O. N. Chupakhin // Tetrahedron: Asymmetry . - 2004. - Vol. 15, № 5. - P859-862 : ил. - Библиогр.: с. 862 (7 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): HETEROCYCLIC AMINES -- CHLORIDE -- KINETIC RESOLUTION Аннотация: Acylation of heterocyclic amines with N-phthaloyl-(S)-alanyl chloride under kinetic resolution conditions resulted in the predominant formation of (S,S)-amides. The diastereoselectivity of resolution depended heavily on the structure of the resolved amine.???? \\\\Expert2\\nbo\\Tetrahedron Asymmetry\\2004, v.15, p.859.pdf |
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???? |
D 53 Diastereoselective synthesis of 3-substituted acylamino-3,4-dihydro-1,2,4-triazinones [Electronic resource] / I. N. Egorov, B. Konig, V. L. Rusinov, O. N. Chupakhin // Mendeleev Communications. - 2008. - Vol. 18, № 2. - P99-101 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: 6-Phenyl-1,2,4-triazin-5(4H)-one 1 reacts with C-nucleophiles, such as indole, in the presence of N-acetylamino acids, to yield 2-acyl-3-indolyl-6-phenyl-3,4-dihydro-1,2,4-triazin-5(4H)-ones 2–6 with high diastereoselectivity \\\\Expert2\\nbo\\Mendeleev Communications\\2008, v.18, p.99.pdf |
K 46 Kinetic resolution of heterocyclic amines by reaction with optically active acid chlorides. The effect of reaction conditions on the diastereoselectivity of acylation of (±)-3-methyl-2,3-dihydro-4H-1,4-benzoxazine [Electronic resource] / V. P. Krasnov, G. L. Levit, M. A. Koroleva, I. M. Bukrina, L. Sh. Sadretdinova, I. N. Andreeva, V. N. Charushin, O. N. Chupakhin // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2004. - Vol. 53, № 6. - P1253-1256 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The influence of the reaction conditions (solvent, base) on the diastereoselectivity of acylation of (±)-3-methyl-2,3-dihydro-4H-1,4-benzoxazine with (S)-naproxen and N-tosyl-(S)-proline chlorides was studied. The highest diastereoselectivity was observed for the reaction carried out in benzene in the presence of aliphatic tertiary amines \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2004, 53 (6), 1253.pdf |
S 90 Study of the effect of the nature of the side chain in esters of amino acids on the diastereoselectivity of condensation with 5(4H)-oxazolone in the synthesis of dipeptides with N-terminal N-acetylphenylalanine [Electronic resource] / V. P. Krasnov, E. A. Zhdanova, N. Z. Solieva, L. Sh. Sadretdinova, I. M. Bukrina, A. M. Demin, G. L. Levit, M. A. Ezhikova, M. I. Kodess // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2004. - Vol. 53, № 6. - P1331-1334 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: Conditions for fast racemization of 5(4H)-oxazolones prepared from N-acylphenylalanine were found. Reactions of 4-benzyl-2-methyl-5(4H)-oxazolone with amino acid esters proceed diastereoselectively to give predominantly dipeptides comprising R-phenylalanine. The diastereoselectivity increases with complication of the structure of the side chain in the amino acid esters \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2004, 53 (6), 1331.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 |
S 90 Study of the inf luence of the alkyl ester group in (S)-valinates on diastereoselectivity of their condensation with N-acetylphenylalanine by the mixed anhydride method [Electronic resource] / E. A. Zhdanova, N. Z. Solieva, L. Sh. Sadretdinova, M. A. Ezhikova, M. I. Kodess, V. P. Krasnov // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2006. - Vol. 55, № 5. - P925-927. - Bibliogr. : p. 927 (15 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): 5(4H)-OXAZOLONES -- AMINO ACIDS -- DIASTEREOSELECTIVITY -- DIPEPTIDES -- DYNAMIC KINETIC RESOLUTION -- RACEMIZATION Аннотация: The dynamic kinetic resolution in the synthesis of alkyl N-acetylphenylalanyl (S)-valinates was studied by the mixed anhydride method. The structure of the ester group of the amino component appeared to exert no substantial effect on the diastereoselectivity of the reaction. \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2006, 55 (5), 925.pdf |
D 62 Direct diastereoselective introduction of l-menthol residue into 1,2,4-triazin-5(4H)-one [Electronic resource] / G. V. Zyryanov, V. L. Rusinov, O. N. Chupakhin, G. L. Levit, M. I. Kodess, T. S. Shtukina // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2004. - Vol. 53, № 6. - P1290-1294. - Bibliogr. : p. 1294 (16 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ACETIC ANHYDRIDE -- DIASTEREOSELECTIVITY -- ISOBUTYRIC ANHYDRIDE -- L-MENTHOL -- NUCLEOPHILIC ADDITION Аннотация: The reaction of 3-phenyl-1,2,4-triazin-5(4H)-one (1) with l-menthol in the presence of aliphatic acid anhydrides results in (6S)- and (6R)-1-acyl-6-(l- menth-3-yl)-1,6-dyhydro-3-phenyl-1,2,4-triazin-5(4H)-ones. The reaction is diastereoselective with predominant formation of (6S)-isomers. The reaction diastereoselectivity increases with enhancement of the steric hindrance in the vicinity of the reaction center of the azine. \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2004, 53 (6), 1290-1294.pdf |
N 10 N-Tosyl-(S)-Prolyl Chloride in Kinetic Resolution of Racemic Heterocyclic Amines [Electronic resource] / D. A. Gruzdev, S. A. Vakarov, G. L. Levit, V. P. Krasnov // Chemistry of Heterocyclic Compounds. - 2014. - Article in Press. - С. 1-13 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): H-[1,4]BENZOXAZINE -- ACYLATION -- AMINES Аннотация: The kinetic resolution of racemic heterocyclic amines via acylation with N-tosyl-(S)-prolyl chloride was systematically investigated. It was established that racemic mixtures of aromatic amines could be resolved with high efficiency, while the acylation of 2- and 3-methylpiperidines occurred with low diastereoselectivity. A method for the preparation of enantiomerically pure (3 R)-7,8-difluoro-3-methyl-3,4-dihydro-2 H-[1,4]benzoxazine was developed |
S 98 Synthesis of chromeno[3,4-c][1,2]oxazine-N-oxides via formal [4+2] cycloaddition of 3-nitro-2-trihalomethyl-2H-chromenes with cyclohexanone and pinacolone enamines [Electronic resource] / V. Yu. Korotaev, A. Yu. Barkov, E. G. Matochkina, M. I. Kodess, V. Ya. Sosnovskikh // Tetrahedron. - 2014. - Vol.70, №34. - С. 5161-5167. - Bibliogr. : p. 5166-5167 (42 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): 2,3,4-TRISUBSTITUTED CHROMANES -- 3-NITRO-2-TRIHALOMETHYL-2H-CHROMENES -- CYCLIC NITRONATES Аннотация: 3-Nitro-2-trichloro(trifluoro)methyl-2H-chromenes undergo a formal [4+2] cycloaddition reaction to cyclohexanone and pinacolone enamines, producing chromeno[3,4-c][1,2]benzoxazin-6-oxides with high diastereoselectivity and in good yields. In addition, some novel 2,3,4-trisubstituted chromanes were obtained. The stereochemistry of the products was established based on a 2D NOESY experiment and an X-ray diffraction study \\\\expert2\\nbo\\Tetrahedron\\2014, v. 70 (34), p. 5161.pdf |
K 46 Kinetic resolution of racemic 6-substituted 1,2,3,4-tetrahydroquinaldines with chiral acyl chlorides. Experiment and quantum chemical simulation / E. N. Chulakov, M. A. Korolyova, L. S. Sadretdinova [et al.] // Russian chemical bulletin. - 2021. - Vol. 70, № 5. - P890-899 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: A comparative study of the kinetic resolution (KR) of racemic 6-substituted 2-methyl-1,2,3,4-tetrahydroquinolines with acyl chlorides of (S)-naproxen, N-phthaloyl-(S)-leucine, and (R)-O-phenyllactic acid was carried out. The selectivity factors in the KR of racemic amines with acyl chlorides of (S)-naproxen and (R)-O-phenyllactic acid were shown to be approximately the same and higher than those for the KR of N-phthaloyl-(S)-leucyl chloride. The reasons for the stereodifferentiation in the KR of racemic tetrahydroquinaldines containing groups of different electronic properties by acyl chlorides of three different chiral acids were explained using the DFT method. The conditions for stabilizing π—π interactions of aromatic fragments of the reagents, which do not occur in the same form in the transition state and lead to the minor diastereoisomeric product, are created in the transition state of the faster acylation reaction with (S)-naproxen and (R)-O-phenyllactic acyl chlorides. In the case of the KR of 2-methyl-1,2,3,4-tetrahydroquinoline and 2-methyl-6-methoxy-1,2,3,4-tetrahydroquinoline with N-phthaloyl-(S)-leucyl chloride, the acylation diastereoselectivity is determined, most likely, by conformational factors. The individual (S)-enantiomer of 2-methyl-6-methoxy-1,2,3,4-tetrahydroquinoline of high optical purity was synthesized using the KR of the racemate with (S)-naproxen acyl chloride. |