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1.
《Tetrahedron: Asymmetry》2001,12(12):1779-1784
Crude Pseudomonas cepacia lipase (Amano PS-30) is a suitable biocatalyst for the kinetic resolution of the 1,2-cis-disubstituted cyclopentanoid building block (3aR*,4R*,6aS*)-(±)-4-hydroxymethyl-3,3a,4,6a-tetrahydrocyclopenta[b]furan-2-one through enantioselective transesterification. Enantiomerically enriched acetic acid (3aS,4S,6aR)-(+)-2-oxo-3,3a,4,6a-tetrahydro-2H-cyclopenta[b]furan-4-yl methyl ester was utilized in a formal synthesis of the iridoids (+)-isoiridomyrmecin and (−)-teucriumlactone. 相似文献
2.
Z. R. Valiullina A. N. Lobov N. K. Selezneva M. S. Miftakhov 《Russian Journal of Organic Chemistry》2016,52(3):349-354
Fused tricyclic aziridines, methyl rel-(2R,2aR,3R,4R,4aR,4bS)- and rel-(2S,2aR,3R,4R,4aR,4bS)-4-hydroxy-2,4a-dimethoxyhexahydro-1-oxa-2b-azacyclopropa[cd]pentalene-3-carboxylates, have been synthesized as possible precursors to β-lactams. The product structure has been determined by two-dimensional NMR techniques in combination with computational methods. 相似文献
3.
Methylation of 5(6)-nitro-1H-benzimidazole with methyl iodide in the presence of potassium hydroxide and N-methylpyrrolidin-2-one gave a mixture of isomeric 1-methyl-5-nitro- and 1-methyl-6-nitro-1H-benzimidazoles which were reduced with tin in concentrated aqueous HCl on heating. The resulting amines reacted with furan-2-carbonyl chloride in N-methylpyrrolidin-2-one to give furan-2-carboxamides which were treated with excess P2S5 in pyridine. Oxidation of isomeric furan-2-carbothioamides with K3[Fe(CN)6] in alkaline medium afforded a mixture of intramolecular cyclization products, 2-(furan-2-yl)-6-methyl-6H-imidazo[4,5-g][1,3]benzothiazole and 2-(furan-2-yl)-8-methyl-8H-imidazo[4,5-g][1,3]benzothiazole which were separated by column chromatography and identified. 相似文献
4.
A. A. Moroz V. E. Zhulanov M. V. Dmitriev D. N. Babentsev A. N. Maslivets 《Russian Journal of Organic Chemistry》2018,54(5):780-784
1H-pyrrol-2,3-diones react with nitrones affording substituted pyrrolо[3,2-d]isoxazoles. The structures of ethyl (3R*,3aR*,6aR*)-6-benzyl-3-(4-bromophenyl)-4,5-dioxo-2,6a-diphenylhexahydro-3aHpyrrolo[ 3,2-d]isoxazole-3a-carboxylate and dimethyl (3R*,3aR*,6aS*)-3-(4-bromophenyl)-4,5-dioxo-2,6-diphenyltetrahydro-3aH-pyrrolo[3,2-d]isoxazole-3a,6a(4H)-dicarboxylate were proved by single-crystal X-ray analysis. 相似文献
5.
V. G. Kasradze E. V. Salimova F. Z. Galin O. S. Kukovinets Z. A. Starikova M. Yu. Antipin 《Journal of Structural Chemistry》2010,51(3):599-602
The (4Z)- {[(1R, 6S)-7,7-dimethyl-2-oxo-3-oxabicyclo[4.1.0]hept-4-en-4-yl]methylene}-2-phenyl-1,3-oxazol-5(4H)-one compound is synthesized and its molecular structure is determined. 相似文献
6.
S. O. Kasatkina E. E. Stepanova M. V. Dmitriev A. N. Maslivets 《Russian Journal of Organic Chemistry》2018,54(10):1515-1518
Hetero-Diels–Alder reaction of 3-aroylpyrrolo[1,2-a]quinoxaline-1,2,4(5H)-triones with styrene afforded diastereoisomeric (5R*,6aR*)- and (5S*,6aR*)-3,5-diaryl-5,6-dihydropyrano[4′,3′:2,3]pyrrolo[1,2-a]-quinoxaline-1,2,7(8H)-triones. 相似文献
7.
Thermally induced [4 + 2]-cycloaddition of 3-aroylpyrrolo[1,2-a]quinoxaline-1,2,4(5H)-triones with alkyl vinyl ethers afforded mixtures of diastereoisomeric (5S*,6aR*)- and (5R*,6aR*)-5-alkoxy-3-aryl-5,6-dihydropyrano[ 4′,3′: 2,3]pyrrolo[1,2-a]quinoxaline-1,2,7(8H)-triones. 相似文献
8.
Airat M. Gimazetdinov Salavat S. Gataullin Ivan S. Bushmarinov Mansur S. Miftakhov 《Tetrahedron》2012,68(29):5754-5758
Diastereomeric amides produced via the cleavage of easily available (±)-7,7-dichloro-4-exo-trimethylsilylbicyclo[3.2.0]hept-2-en-6-one by treatment with (+)-α-methylbenzylamine were transformed into bicyclic lactam-aminals, which can easily be separated by column chromatography on SiO2. The latter products lead to enantiomeric (3a,6a)-4-hydroxy-3,3a,4,6a-tetrahydro-1H-cyclopenta[c]furan-1-ones after the removal of the chiral auxiliary and epoxidation. 相似文献
9.
E. E. Stepanova M. V. Dmitriev A. N. Maslivets 《Russian Journal of Organic Chemistry》2017,53(12):1851-1856
The hetero-Diels–Alder reaction of 3-aroylpyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones with styrene afforded mixtures of diastereoisomeric (10R*,11aR*)- and (10S*,11aR*)-8-aryl-10-phenyl-10,11-dihydropyrano[4′,3′: 2,3]pyrrolo[2,1-c][1,4]benzoxazine-6,7,12-triones. 相似文献
10.
A. Yu. Ledneva N. G. Naumov A. V. Virovets S. Cordier Y. Molard 《Journal of Structural Chemistry》2012,53(1):132-137
The structures of three novel octahedral rhenium cluster compounds [Re6S8(CN)2(py)4]·H2O (1), [Re6S8(CN)2(4-Mepy)4] (2), [Re6S8(CN)2(4-Mepy)4]·4-Mepy (3) (py = pyridine, 4-Mepy = 4-methylpyridine) are determined by X-ray crystallography. Crystal data are: C2/m space group, a = 14.813(1) Å, b = 14.772(1) Å, c = 9.2122(6) Å, β = 119.085(2)°, V = 1761.7(2) Å3, d x = 3.318 g/cm3, R = 0.0585 (1); I41/amd space group, a = 16.0018(3) Å, c = 14.7186(5) Å, V = 3768.81(16) Å3, d x = 3.169 g/cm3, R = 0.0489 (2); P21/c space group, a = 9.0452(4) Å, b = 15.8065(7) Å, c = 15.2951(6) Å, β = 103.700(2)°, V = 2124.57(16) Å3, d x = 2.957 g/cm3, R = 0.0245 (3). Molecular cluster complexes interact via π-π stacking affording 3D frameworks in 1 and 2 and chains in 3. 相似文献
11.
N. A. Ivanova V. A. Akhmetyanova N. P. Akhmetdinova O. V. Shitikova K. Yu. Suponitzky M. S. Miftakhov 《Russian Journal of Organic Chemistry》2014,50(6):810-814
Baeyer-Villiger oxidation of racemic [2 +2 ]-cycloadduct derived from dichloroketene and dimethylfulvene gave 3,3-dichloro-6-(1-methylidene)-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]furan-2-one, and opening of the lactone ring in the latter with (+)-α-methylbenzylamine produced diastereoisomeric amides which can be readily separated by chromatography on silica gel. The subsequent lactonization and reductive dechlorination afforded enantiomeric (?)- and (+)-6-(propan-2-ylidene)-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]-furan-1-ones. 相似文献
12.
R. P. Litvinovskaya M. A. Aver'kova A. S. Lyakhov N. V. Koval' A. V. Baranovskii V. A. Khripach 《Russian Journal of General Chemistry》2005,75(8):1276-1279
The crystal and molecular structure of (4′R,5′R,22R)-22-hydroxy-22-(3′, 4′-dimethylisoxazolin-5′-yl)-6β-methoxy-3α,5-cyclo-23,24-dinorcholane was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic system, space group C2; a 19.649(7), b 7.680(2), c 17.254(6) Å; β 101.05(3)°. The only diastereomer formed by the 1,3-dipolar cycloaddition of acetonitriole oxide has the 4′R,5′R stereochemistry of the arising chiral centers. The conformation of the side chain of the molecule is additionally stabilized by an intramolecular hydrogen bond. 相似文献
13.
G. A. Kachkovskii N. V. Andrushko S. Yu. Sheiko O. I. Kolodyazhnyi 《Russian Journal of General Chemistry》2005,75(11):1735-1743
Stereochemistry of addition of di- and trialkyl phosphites to C=N compounds was investigated. Reactions of achiral dialkyl phosphites with chiral aldimines as well as that of chiral di-(1R,2S,5R)-menthyl phosphite with achiral aldimines result in low diastereomeric enrichment of the addition compound. Reaction stereoselectivity increased when supplementary chiral inductor was introduced to the reaction system. Reaction of di-(1R,2S, 5R)-menthyl phosphite with (S)-α-methylbenzylbenzaldimine proceeds as concerted asymmetric induction to form practically one diastereomer of N-substituted aminophosphonic acid. However, reaction of di-(1R,2S, 5R)-menthyl phosphite with (R)-α-methylbenzylbenzaldimine proceeded as not concerted asymmetric induction, and diastereomeric enrichment of the product was low. By chemical extrapolation, absolute configuration of compounds formed was established. Tri-(1R,2S,5R)-menthyl phosphite reacts with C=N compounds in the presence of boron trifluoride etherate to form aminophosphonic acid derivatives with the absolute configuration opposite to that appearing in the reaction of di-(1R,2S,5R)-menthyl phosphite with the same C=N compounds. 相似文献
14.
A. E. Sibiryakova A. N. Reznikov V. B. Rybakov Yu. N. Klimochkin 《Russian Journal of Organic Chemistry》2017,53(2):153-156
Synthesis was performed of individual methyl [(S,2R,3S)-4-nitro-1-oxo-1,3-diphenylbutan-2-yl]-(phenyl)phosphinate from racemic β-keto phosphinate and ω-nitrostyrene under the catalysis by nickel(II) complex with (1R,2R)-N,N'-dibenzylcyclohexane-1,2-diamine. 相似文献
15.
E. V. Kabin V. A. Emel’yanov I. A. Baidina T. I. Nedoseykina V. A. Vorob’yov 《Journal of Structural Chemistry》2010,51(1):73-80
The structure of trans-[RuNO(NH3)4(H2O)](NO3)3 (I) and trans-[RuNO(NH3)4(NO3)](NO3)2 (II) was determined by XRD. Crystallographic data are as follows: space group I41/a; a = b = 18.280(1) Å, c = 15.129(1) Å, R = 0.0244 (I), and space group Cm, a = 11.5620(3) Å, b = 7.9934(2) Å, c = 7.7864(2) Å, β = 127.124(1)°, R = 0.0139 (II). Interatomic distances for complex particles of fac- and mer- [RuNO(NH3)2(NO3)3] (III and IV, respectively) were determined by EXAFS. 相似文献
16.
Beeranahally H. Doreswamy Madegowda Mahendra Sridhar M. Anandalwar Javaregowda S. Prasad Kempegowda Mantelingu Basappa Kanchugarakoppal S. Rangappa 《Central European Journal of Chemistry》2003,1(4):477-490
The isolation of stable carbenes of the Arduengo (1a) and Wanzlick (2a) type has prompted us to look for stable nitrenium ions of the related structural type 1-ethyl-3-(phenyl)-1,2,3-triazolium perchlorate (6+). The title compound C10H14Cl N3O4 was isolated and structure was investigated by X-ray crystallography. It crystallizes in the monoclinic space group P21/c with cell parameters a=6.697(4) Å, b=9.724(9) Å, c=19.844(2) Å and Z=4. The final residual factor is R1=0.0471 for 1545 reflections with I>2σ(I). The structure exhibits intermolecular hydrogen bonds. 相似文献
17.
H. X. Ma N. N. Zhao B. Yan Y. L. Guan J. F. Li J. R. Song 《Journal of Structural Chemistry》2012,53(3):534-541
Bis-(3,3-dinitroazetidinyl)-oxamide ((DNAZ-CO)2) is an acyl derivative of 3,3-dinitroazetidine (DNAZ). It is prepared and its crystal structure is determined. The crystal is orthorhombic, Fdd2 space group, a = 13.136(14) Å, b = 19.48(3) Å, c = 10.326(14) Å, V = 2642 (6) Å3, Z = 8. A density functional theory (DFT) method of the Amsterdam Density Functional (ADF) package is used to calculate the geometry, frequencies, and properties. The optimized geometry, frontier orbital energy, and main atomic orbital percentage are obtained. The thermal behavior is studied under a non-isothermal condition by DSC and TG/DTG methods. The apparent activation energy (E a) and pre-exponential factor (A) of the exothermic decomposition reaction of (DNAZ-CO)2 are 164.10 kJmol?1 and 1013.38 s?1 respectively. The critical temperature of thermal explosion is 272.20°C. The values of ΔS ≠, ΔH ≠, and ΔG ≠ of this reaction are 6.44 Jmol?1·K?1, 163.76 kJmol?1 and 160.34 kJmol?1 respectively. 相似文献
18.
L. O. Nindakova N. M. Badyrova V. V. Smirnov V. O. Strakhov S. S. Kolesnikov 《Russian Journal of General Chemistry》2016,86(6):1240-1249
Hydrogen transfer hydrogenation of acetophenone and methyl benzoylformate with 2-propanol was studied on colloidal systems obtained by reduction of rhodium complexes in the presence of optically active compounds: chiral diamines, quaternary salt (4S,5S)-(–)-N1,N4-dibenzylene-2,3-dihydroxy-N1,N1,N4,N4-tetramethylbutane-1,4-diammonium dichloride and (8S,9R)-(–)-cinchonidine. The increase in the molar ratio modifier/Rh leads to the increase in the enantioneric excess (ee) of the reaction products. The largest ee [43.8% of (R)-1-phenylethanol and 58.2% of methyl ester of (R)-mandelic acid] were achieved for the ratios (8S,9R)-(–)-cinchonadine: Rh = 9: 1 and 3: 1, respectively. The catalyst was characterized by the high-resolution transmission electron microscopy, X-ray diffraction analysis, and thermal analysis. 相似文献
19.
A. E. Sibiryakova A. N. Reznikov V. B. Rybakov Yu. N. Klimochkin 《Russian Journal of General Chemistry》2016,86(11):2477-2483
Chiral ligands—derivatives of (1R,2R)-cyclohexane-1,2-diamine, (1R,2R)-diphenylethane-1,2-diamine, and (2S,3S)-bicyclo[2.2.2]octane-2,3-diamine—and octahedral Ni(II) complexes on their basis have been synthesized. 相似文献
20.
N. B. Morozova P. A. Stabnikov I. A. Baidina P. P. Semyannikov S. V. Trubin I. K. Igumenov 《Journal of Structural Chemistry》2007,48(5):889-898
Copper(II) chelates with β-diimine derivatives of acetylacetone that have a general formula of Cu(R1C(NR2)CHC(NR2)R1)2, where R1, R2 are alkyl substituents, are synthesized. The complexes were identified using elemental analysis, melting point measurements, and high-temperature mass spectrometry data. Knudsen technique is employed to determine the vapor pressure temperature dependence, and standard thermodynamic parameters of sublimation ΔH T 0 and ΔS T 0 are derived. A single crystal X-ray diffraction study is carried out for copper(II) complexes of Cu(CH3-C(NCH3)-CH-C(NCH3)-CH3)2 (a = 10.363(1) Å, b = 11.978(1) Å, c = 12.653(1) Å, V = 1570.6(3) Å3, space group Pnc2, Z = 4, d calc = 1.328 g/cm3, R = 0.027), Cu(CH3-C(NC2H5)-CH-C(NC2H5)-CH3)2 (a = 11.782(4) Å, b = 13.951(8) Å, c = 25.591(8) Å, V = 4206(3) Å3, space group C2221, Z = 8, d calc = 1.169 g/cm3, R = 0.10), and also 2-(methylamino)-4-(methylimino)-pentene-2 CH3-(C=(NCH3))-CH=(C-(NHCH3))-CH3 (a = 12.129(2) Å, b = 12.034(2) Å, c = 5.692(1) Å, β = 107.05(3)°, V = 794.3(3) Å3, space group Cc, Z = 4, d calc = 1.055 g/cm3, R = 0.06). Van der Waals lattice energy E cryst is calculated for the cooper(II) complexes by the atom-atom potential technique. The calculated values are compared to experimental sublimation enthalpies Δ H T 0 . 相似文献