共查询到20条相似文献,搜索用时 15 毫秒
1.
R. N. Shakhmaev A. Sh. Sunagatullina D. A. Akimova V. V. Zorin 《Russian Journal of Organic Chemistry》2017,53(4):615-617
An efficient synthetic approach to 2E,4E and 2E,4Z isomers of ethyl 5-chloropenta-2,4-dienoate has been developed on the basis of one-pot oxidation–olefination of readily accessible (E)- and (Z)-3-chloroprop-2-en-1-ols by the action of barium manganate and ethyl (triphenyl-λ5-phosphanylidene)acetate. 相似文献
2.
Vera L. M. Silva Artur M. S. Silva Diana C. G. A. Pinto José A. S. Cavaleiro Attila Vasas Tamás Patonay 《Monatshefte für Chemie / Chemical Monthly》2008,139(11):1307-1315
Several (E)- and (Z)-3-styrylchromones were prepared by two different methodologies, the Wittig reaction of chromone-3-carboxaldehyde with benzylic ylides and the Knoevenagel condensation of chromone-3-carboxaldehyde with phenylacetic acids in the presence of potassium tert-butoxide under microwave irradiation. The Knoevenagel reaction followed by a decarboxylation offered an efficient and diastereoselective method for preparing (E)-3-styrylchromones in a shorter reaction time. It was also demonstrated that phenylacetic acid can also be substituted with
success by phenylmalonic acid. The stereochemistry of all products was assigned by NMR experiments.
Correspondence: Artur M. S. Silva, Chemistry Department, University of Aveiro, 3810-193 Aveiro, Portugal. 相似文献
3.
M. V. Musalova A. G. Khabibulina V. A. Potapov S. V. Amosova 《Russian Journal of Organic Chemistry》2017,53(10):1593-1595
A procedure for the stereoselective synthesis of dichloro[(Z)-2-chloro-2-phenylethenyl][(4E)-5- chlorooct-4-en-4-yl]-λ4-tellane and [(Z)-2-chloro-2-phenylethenyl][(4E)-5-chlorooct-4-en-4-yl]tellane has been developed on the basis of anti-addition of tellurium tetrachloride–phenylacetylene monoadduct to oct-4-yne. 相似文献
4.
Vera L. M. Silva Artur M. S. Silva Diana C. G. A. Pinto José A. S. Cavaleiro José Elguero 《Monatshefte für Chemie / Chemical Monthly》2009,140(1):87-95
Abstract An efficient synthesis method for the preparation of a series of new (Z)- and (E)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles was developed. The reaction of (Z)- and (E)-3-styrylchromones with hydrazine hydrate afforded the corresponding (Z)- and (E)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles, except for nitro derivatives, where both (Z)- and (E)-4′-nitro-3-styrylchromones afforded (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles. The reaction mechanism for these transformations is discussed and the
stereochemistries of all products were established by NMR experiments.
Graphical abstract
相似文献
5.
T. F. Ibragimov M. G. Levkovich V. A. Saprykina Kh. M. Shakhidoyatov 《Chemistry of Natural Compounds》2010,46(5):767-770
N-Chloroacetylcytisine was synthesized by acylation of (–)-cytisine. Stable Z- and E-conformers with respect to rotational isomerism around the N-12–CO bond were found in PMR spectra at room temperature. The
point at which PMR resonances of the Z- and E-conformers coalesced upon heating was measured. The transition barrier between the conformers was estimated. 相似文献
6.
Methyl (Z)-3-bromo-3-(4-methylbenzenesulfonyl)prop-2-enoate reacted with acetylacetone in THF in the presence of sodium hydride (3 h, 50°C) to give methyl (E)-3-acetyl-2-[(4-methylbenzenesulfonyl)-methylidene]-4-oxopentanoate as the only product. According to the X-ray diffraction data, the crystalline product has enol structure. 相似文献
7.
U. S. Makhmudov Sh. B. Rakhimov B. Tashkhodzhaev M. G. Levkovich V. I. Vinogradova 《Chemistry of Natural Compounds》2008,44(2):208-212
The molecular structures of N-(o-and p-hydroxybenzyl)cytisine were investigated by NMR spectroscopy, x-ray structure analysis, and molecular modeling. It was found
that NMR resonances of the OH and aromatic protons in N-(o-hydroxybenzyl)cytisine were doubled because of the presence of two conformers in solution.
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Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 165–168, March–April, 2008. 相似文献
8.
Previously unknown E isomers of azomethines (Schiff bases) were synthesized from vanillal and vanillin esters by their reaction with cyclohexylamine. 相似文献
9.
2-(N-cytisinyl)acetamide or 3-(N-cytisinyl)propanamide were prepared by treatment of the methyl esters of N-cytisinylacetic or 3-(N-cytisinyl)propanoic acids with aqueous NH4OH. N-(2-Aminoethyl)-or N-(3-aminopropyl)cytisine was synthesized by reduction of the amide with (i-Bu)2AlH. 相似文献
10.
A number of (Z)-N,N-dialkyl- and (Z)-N-acyl-N-alkyl-O-methylnicotinamide oximes was synthesized. Their configuration was confirmed by the NOESY experiment. Evaluation of fungicidal
activity of compounds obtained was performed. 相似文献
11.
12.
D. Ashok M. Ziauddin B. Vijaya Lakshmi M. Sarasija 《Russian Journal of General Chemistry》2016,86(7):1753-1757
Aurones, pyrazole and thiophene scaffolds are known for their potential antimicrobial activity. Herein, we have synthesized hybrid compounds containing three substituted (Z)-2-{[1-phenyl-3-(thiophen-2-yl)- 1H-pyrazol-4-yl]methylene}benzofuran-3(2H)-ones that had been produced from substituted (E)-1-(2-hydroxyphenyl)- 3-[1-phenyl-3-(thiophen-2-yl)-1H-pyrazol-4-yl]prop-2-en-1-ones in high yields. All synthesized compounds were tested in vitro for their antimicrobial activity. Several of those demonstrated promising activity against some fungal and bacterial strains. 相似文献
13.
N. A. Ivanova Z. R. Valiullina O. V. Shitikova L. V. Spirikhin M. S. Miftakhov 《Russian Journal of Organic Chemistry》2008,44(3):335-339
(2S,3S,4S)-2,3-O-Isopropylidene-4-(methoxycarbonylmethyl)cyclopentan-1-one was synthesized starting from D-ribose through methyl (Z)-3-(5-acetyl-2,2-acetoxyacetyl-2,2-dimethyl-1,3-dioxolan-4-yl)prop-2-enoate which was subjected to cyclization in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, followed by decarboxylation. 相似文献
14.
E. N. Klimovitskii A. N. Galyautdinova A. B. Dobrynin V. V. Gavrilov S. G. Gnevashev R. M. Vafina I. A. Litvinov Yu. G. Shtyrlin 《Russian Journal of Organic Chemistry》2009,45(10):1442-1444
(Z)-But-2-ene-1,4-dithiol was found to undergo isomerization into the E isomer. Condensation of (Z)- and (E)-but-2-ene-1,4-dithiols with acetaldehyde gave isomeric fourteen-membered bis-dithioacetals whose structure was determined
by X-ray analysis. 相似文献
15.
O. G. Strukov V. B. Kondrat’ev Z. V. Vlasova V. A. Petrunin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2017,91(1):100-105
Conformers of the biologically active compounds CH3P(O)(OR)(SCH2CH2NR 2 ′ ), where (I) R = i-C4H9, R′ = C2H5 and (II) R = C2H5, R′ = i-C3H7, are calculated within the AM1 level of theory. The elongated and twisted forms with maximum and minimum distances between a nitrogen atom and those of a phosphorus tetrahedron, respectively, and bearing a syn and anti oriented alkoxy group relative to a phosphoryl oxygen, are studied. It is found that the differences between the energy, electronic, and geometric parameters of these forms are apparent in differences between their properties, e.g., the ability to participate in complexation and protonation, reactions that to some extent simulate the interaction between a substance and a biological object. 相似文献
16.
R. R. Muslukhov A. Kh. Shayakhmetova O. O. Shakhanova M. P. Yakovleva G. Yu. Ishmuratov A. G. Tolstikov 《Chemistry of Natural Compounds》2009,45(5):637-640
Formation of new asymmetric centers with primarily the (S)-configuration was induced by the optically active center of (R)-octadec-9Z-en-7-ol upon Prilezhaev dihydroxylation. This was proved by cyclization of a 1,3-glycol system (de 26%) into the corresponding
1,3-dioxane stereoisomers. 相似文献
17.
For the purpose of investigation of the electronic structures of functionalized pyrroles with potential biological activity the electronic structures and ionization spectra of S-cis-(Z)-2-(2-formylethenyl)pyrrole (FP) were calculated by the propagator quantum chemical method. The calculations were performed using the third-order algebraic diagrammatic construction method (ADC(3)) for one-particle Green´s function (electronic propagator) and the 6–31G** basis set. Going from FP (possessing the intramolecular hydrogen bond H?O) to its conformation FPR (without H?O bonding), the O1s-ionization energy and the ionization energy of the σ-type lone electron pair orbital of the O atom decrease by ~0.2 eV, which is a consequence of stopping the electron density transfer from the O atom. A strong electron density transfer through the hydrogen bond from the O atom to the NH group occurs in the nitrogen core level ionization spectrum as evidenced by a lower N1s-ionization energy of FP (by ~0.7 eV ) compared to that of FPR. The valence shell ionization spectra of FP and FPR calculated using the ADC(3) method are characterized by a high density of the satellite states. The results obtained indicate that the electronic structures of the compounds of the considered class are characterized by pronounced effects of electron correlation. 相似文献
18.
D. Q. Hoang E. Ya. Borisova N. Yu. Borisova N. Yu. Asilova O. S. Kaldyrkaeva E. V. Arzamastsev O. A. Terekhova E. Yu. Afanas’eva E. L. Levitskaya 《Russian Chemical Bulletin》2018,67(1):131-136
N-(2-Aminoethyl)-N-(2-hydroxy-2-phenylethyl)carboxamides were synthesized from styrene oxide by ring opening with N,N-disubstituted ethylenediamines followed by N-acylation. Synthesized compounds have pronounced antiarrhythmic activity and low toxicity. 相似文献
19.
Chiral dialkyl- and tetraalkylglycolurils have been obtained using chiral (S)-(+)- and (R)-(-)-1-sec-butyl-3-methylurea as starting materials. The diastereomer (S)-(+)-2,6-di-sec-butyl-4,8-dimethyl-2,4,6,8-tetraazabicyclo[3.3.0]-octane-3,7-dione was separated into stereoisomers, for the higher melting of which the absolute configuration was determined as (S,S,S,S) by X-ray structural analysis. 相似文献
20.
I. V. Ukrainets E. V. Mospanova A. V. Turov V. A. Parshykov 《Chemistry of Heterocyclic Compounds》2011,47(6):731-736
The alkylation of 3-(2-hydroxyethyl)-1H,3H-quinazoline-2,4-dione and subsequent bromination of its 1-allyl derivative have
been studied. The data obtained has been compared with the results of similar studies on a series of other, related compounds.
A rule has been formulated which allows a prediction of 1-allyl-substituted 2-oxo azaheterocycles bromination route based
upon the way in which their initial alkylation by allyl bromide in the system DMSO–K2CO3 occurs. 相似文献