共查询到20条相似文献,搜索用时 11 毫秒
1.
Dmitriy M. Volochnyuk Dmitriy A. Sibgatulin Alexander N. Chernega 《Tetrahedron》2005,61(11):2839-2847
The reaction of 1,1,1,5,5,5-hexafluoroacetylacetone with push-pull enamines having a methyl group at the α-position was investigated. It was found that the reaction is sensitive both to the structure of enamines and to reaction conditions. As a result, a set of bistrifluoromethyldialkylanilines and ethyl bistrifluoromethylsalicylate was prepared. Plausible mechanisms and factors influencing the course of the reaction are discussed. 相似文献
2.
A. V. Zerov T. S. Krupenya A. A. Petrov S. I. Yakimovich 《Russian Journal of Organic Chemistry》2016,52(3):312-318
Carbonic dihydrazide reacted with 2 equiv of trifluoroacetylacetone to give a compound containing 5-hydroxy-4,5-dihydropyrazole and keto enehydrazine fragments. Analogous 2 : 1 condensations of trifluoro-acetylacetone and 4-ethoxy-1,1,1-trifluorobut-3-en-2-one with oxalohydrazide and malonohydrazide afforded bis(5-hydroxy-4,5-dihydropyrazole) structures as two diastereoisomers. 相似文献
3.
Dmitriy M Volochnyuk Dmitriy A Sibgatulin Alexander N Chernega Alexander M Pinchuk Andrei A Tolmachev 《Tetrahedron》2004,60(10):2361-2371
The reaction of β-trifluoroacetylvinyl ethers with ‘push-pull’ enamines having a methyl group at the α-position was investigated. As a result, a set of CF3-containing dialkyl anilines and their covalent hydrates were obtained. A possible reaction mechanism and the stability of the covalent hydrates obtained are discussed. 相似文献
4.
The introduction of a 1,3-diacetylpyridine moiety, as an additional binding niche in a macrocyclic receptor ligand containing a conjugated, push-pull malonate functionality, leads to, in addition to the 1:1 binding stoichiometry, the equilibrium formation of multiple complexes, specifically 1:2, 2:1, and 3:1 ligand:metal complexes with lanthanide trications. Various binding modes elicit distinctive responses in the visible region, which enhance the potential recognition of lanthanide ions. This paper also highlights the usefulness of a full factor analysis in the elucidation of complex binding phenomena. 相似文献
5.
The reaction of 2-chloro-3-oxo-3,4-dihydro-2H-1,4-benzothiazines with ‘push-pull’ enamines was investigated. The reaction with the enamines occurs at the β-carbon atom in the presence of a small excess of triethylamine. As a result, a set of 3-oxo-3,4-dihydro-2H-1,4-benzothiazin-2-yl derivatives of 1,3-dicarbonyl compounds and benzothiazinone spiro derivatives was prepared. On acidic hydrolysis of ethyl 2-ethyl-3-(methylimino)-2-(3-oxo-3,4-dihydro-2H-1,4-benzothiazin-2-yl)butanoate, a new rearrangement affording ethyl 11-ethyl-2,3-dimethyl-4-oxo-2,3,4,5-tetrahydro-1H-2,5-methano-6,1,3-benzothiadiazocine-11-carboxylate was discovered. A plausible mechanism and factors influencing the course of the reaction are discussed. 相似文献
6.
Yves R Dumond 《Tetrahedron》2004,60(6):1345-1352
Tetra-substituted zirconacyclopentadiene derivatives, obtainable via in situ generation of zirconacyclopropenes and their cyclic carbozirconation with alkynes, can be treated with alkynyllithiums to induce 1,2-migration accompanied by aromatization and protonolysis, leading to the formation of penta-substituted benzene derivatives, in which all five substituted may be different. 相似文献
7.
Ya. V. Burgart A. S. Fokin I. T. Bazyl' V. I. Saloutin 《Russian Chemical Bulletin》1997,46(5):952-954
The reaction of fluoroalkyl-containing 1,3-dicarbonyl compounds with benzylideneacetone with the use of pyridine or triethylamine
as a catalyst gave new 3-fluoroalkyl-4-ethoxycarbonyl(acyl)-5-phenylcyclohexan-3-ol-I-ones in yields of 16–33%.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 992–994, May, 1997. 相似文献
8.
Mladen V. Proštenik Miljenko Dumić Nada Bošnjak 《Monatshefte für Chemie / Chemical Monthly》1980,111(3):771-773
Reaction of 1,3-dicarbonyl compounds with nitryl chloride through substitution on the activated methylene group, resulted in the formation of chloro, dichloro and oximino derivatives.
Die Reaktion der 1,3-Dicarbonylverbindungen mit Nitrylchlorid
Zusammenfassung Umsetzung von 1,3-Dicarbonylverbindungen mit Nitrylchlorid ergab die entsprechende Chloro-, Dichloro- und Oximinoderivate in einer Substitutionsreaktion an der aktivierten Methylengruppe.相似文献
9.
10.
N-Acetylimidazole is a commonly used acylating reagent. When it is allowed to react with several typical enamines, amides are produced rather than the expected acylated enamines. 相似文献
11.
12.
A series of triazole analogues of the nanaomycin family of antibiotics have been prepared using a ‘click’ dipolar cycloaddition of a naphthalene azide to various alkynes, followed by oxidation to the desired pyranonaphthoquinones. 相似文献
13.
Reaction of dibenzoylmethane with (diacetoxyiodo)benzene in the presence of KOH in MeCN quantitatively gave the corresponding iodonium ylide, which was treated with a HF reagent to afford the corresponding 2-fluorinated dibenzoylmethane in 14-50% yields. The similar reaction of the iodonium ylides obtained from 1-phenylbutan-1,3-dione, ethyl benzoylacetate, and ethyl p-nitrobenzoylacetate with TEA·3HF gave the corresponding fluorinated products in 17-34% yields. It is suggested that the fluorinated products were formed through the C-protonation of the ylide, followed by displacement with fluoride ion. The same reaction of the iodonium ylide of dibenzoylmethane with concentrated HCl gave the corresponding chlorinated product in 45% yield. 相似文献
14.
Different headspace solid-phase microextraction (HS-SPME) methods have been selected and applied to the analysis of volatile compounds in ‘fino’ sherry wine by gas chromatography-mass spectrometry. A method based on rotary and continuous liquid-liquid extraction (LLE) for analysis of these same compounds has been optimised. The best conditions to extract this type of compounds using SPME and LLE were determined and both methods were validated. Both methodologies show adequate detection and quantitation limits, and linear ranges for correctly analysing these compounds. The recoveries obtained were close to 100%, with good repeatability values. The analytical and procedural advantages and disadvantages of these two methods have been compared. In general, SPME presented higher sensitivities. Both analytical methods were used to analyse five samples of ‘fino’ sherry wine supplied by different producers. No significant differences were found between the techniques at a significance level of 5%. The regression coefficients (r2) for analysis using LLE and SPME exceeded 0.94 for all compounds. The LLE procedure is a method with high repeatability and has the possibility of simultaneous extraction of several samples (up to 12), however the SPME technique is a solvent-free method presenting major advantages, such as small sample volume and higher sensitivity and simplicity. 相似文献
15.
Irena Akhrem Dzhul’etta Avetisyan Lyudmila Afanas’eva Nikolai Kagramanov Pavel Petrovskii Alexander Orlinkov 《Tetrahedron letters》2010,51(6):907-911
A novel ‘alkane-like’ methodology for the direct and very simple one-pot functionalization of amides and an ester of 1-adamantanecarboxylic acid provides access to new and synthetically challenging 1,3-dicarbonyl-containing adamantanoid compounds with the same or different functional groups. 相似文献
16.
Guilherme Rocha Pereira 《Tetrahedron letters》2010,51(7):1022-651
A bis-malonate C60 derivative bearing terminal alkyne groups prepared by the Bingel reaction has been used as a building block under copper-catalyzed azide-alkyne cycloaddition conditions to produce a series of new fullerene glycoconjugate derivatives. 相似文献
17.
Tanmay Chatterjee 《Tetrahedron letters》2010,51(52):6906-6910
Two symmetrical and one unsymmetrical ‘push-pull’ amphiphilic 2,2′-bipyridine chromophores have been synthesized through Horner-Wordsworth-Emmons and Knoevenagel reaction mechanized synthetic protocols and characterized by spectroscopy. Linear optical properties and thermal stability of the synthesized chromophores have been investigated. 相似文献
18.
Two linear compounds 1 and 2 have been designed and synthesized as new receptors for zinc porphyrins. Both compounds consist of two folded aromatic amide moieties, which are connected with an acetylene linker in 1 or directly in 2. The rigid conformations of their folded moieties are stabilized by intramolecular tri-centered hydrogen bonding, while the whole molecule adopts a ‘S’- or ‘C’-styled conformation depending on the relative orientation of the two rigid moieties. Two pyridine units are introduced at the ends of 1 and 2 for the complexation of zinc porphyrin guests. Although the 1H NMR investigation indicated that both compounds can bind two zinc porphyrin guests at high concentrations (≥5 mM) in chloroform, the UV-vis studies revealed that, at low concentration of 1 and 2 (4 μM), both compounds complex one zinc porphyrin guest to form structurally unique ‘two-point’-bound 1:1 complexes. The association constants of the 1:1 complexes have been determined with the UV-vis titration experiments. 相似文献
19.
V. I. Saloutin Z. É. Skryabina Ya. V. Burgart S. V. Kiseleva 《Russian Chemical Bulletin》1992,41(11):2046-2050
In the reaction of fluorinated copper(II) 1,3-diketonates with diethylenetriamine (or triethylenetetramine) in CHCl3, N,N-bis(1,3-aminovinylketones) are formed in 21–35% yields. Fluorine-containing 1,3-diketones and 1,3-ketoesters, upon interaction with polyamines without solvent, undergo acid cleavage, forming the corresponding amides. The copper(II) 1,3-ketoesterates are readily cleaved in CHCl3 at 25°C in excess triethylenetetramine or ethylenediamine.Department of Fine Organic Synthesis, Institute of Organic Chemistry, Ural Branch, Russian Academy of Sciences, 620219 Ekaterinburg. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2591–2596, November, 1992. 相似文献
20.
Sotir Zahariev Corrado Guarnaccia Luca Quaroni Sándor Pongor 《Tetrahedron letters》2006,47(25):4121-4124
We developed an efficient, cost effective strategy for Fmoc-based solid phase synthesis of ‘difficult’ peptides and/or peptides containing Asp/Asn-Gly sequences, free of aspartimide and related products, using a peptoid methodology for the preparation of N-substituted glycines. 相似文献