Huisgen reaction of (E)-1,5-diarylpent-2-en-4-yn-1-ones and (E)-1,5-diarylpent-1-en-4-yn-3-ones afforded 1-aryl-3-(5-aryl-1H-1,2,3-triazol-4-yl)prop-2-en-1-ones and 3-aryl-1-(5-aryl-1H-1,2,3-triazol-4-yl)-prop-2-en-1-ones, respectively. (E)-1-Aryl-3-(5-phenyl-1H-1,2,3-triazol-4-yl)prop-2-en-1-ones reacted with hydrazine hydrate and phenylhydrazine to give 72-93% of 4-(3-aryl-4,5-dihydro-1H-pyrazol-5-yl)-5-phenyl-1H-1,2,3-triazoles which underwent dehydrogenation on heating in boiling acetic acid with formation of the corresponding pyrazole derivatives. The molecular structures of (E)-3-phenyl-1-(5-phenyl-1H-1,2,3-triazol-4-yl)prop-2-en-1-one and 4-[3-(4-methylphenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-5-yl]-5-phenyl-1H-1,2,3-triazole were studied by X-ray analysis. 4-(3-Aryl-4,5-dihydro-1H-pyrazol-5-yl)-5-phenyl-1H-1,2,3-triazoles showed toxicity against Daphnia magna.
Stereoselective, Cascade Synthesis of trans-Enynones through Coupling-Isomerization Reaction
摘要:
A mild, cascade methodology based on the modified Cadiot-Chodkiewicz reaction was developed for the stereoselective synthesis of trans-enynones. By this methodology, structurally divergent trans-enynones, which are embedded with sensitive functional groups, were synthesized. Control experiments suggested that the CuCl alone does not have a role in the isomerization step, whereas the CuCl piperidine complex (formed during the cross coupling) may have a rate enhancing effect. Furthermore, additional sets of control experiments favor the involvement of unimolecular [1,2]-H shift rather than a homobimolecular proton abstraction during the isomerization step.
Applications of Thermal Activation, Ball-milling and Aqueous Medium in Stereoselective Michael Addition of Nitromethane to Enynones Catalyzed by Chiral Squaramides
作者:Żaneta A. Ignatiuk、Mikołaj J. Janicki、Robert W. Góra、Krzysztof Konieczny、Rafał Kowalczyk
DOI:10.1002/adsc.201801498
日期:2019.3.5
to conjugated en‐ynones was performed through the application of chiral squaramides. Three non‐classical approaches to promote the addition reaction were tested, including activation of the nucleophile by inorganic base in a biphasic aqueous system, thermal activation, and ball‐milling. Hydrogen‐bonding catalysis was effective in all these methods, providing 1,4‐addition products in high yields and
Stereoselective synthesis of enynones via base-catalyzed isomerization of 1,5-disubstituted-2,4-pentadiynyl silyl ethers or their alcohol derivatives
作者:Jingjin Chen、Guoqin Fan、Yuanhong Liu
DOI:10.1039/c0ob00344a
日期:——
1,5-Disubstituted-2,4-pentadiynyl silylethers undergo smooth desilylative isomerization to afford cis-enynones as major products with moderate stereoselectivities in the presence of a catalytic amount of KOtBu or DBU. While the isomerization reactions of their alcohol derivatives catalyzed by KOH, KOtBu or NaH take place efficiently to produce trans-enynones with high stereoselectivities. These reactions
1,5-二取代的2,4-戊二炔基甲硅烷基醚经过顺式脱甲硅烷基化异构化反应,以顺式-乙炔酮为主要产物,并在催化量的二甲基甲酰胺存在下,具有中等的立体选择性。KO Ť卜 或者 DBU。而其醇衍生物的异构化反应是通过酸值, KO Ť卜 或者 碳酸氢钠有效地产生具有高立体选择性的反式-乙炔酮。这些反应为合成具有广泛取代基的烯酮提供了方便实用的途径。
Nucleophilic addition of heterocyclic amines to conjugated enyne ketones
作者:A. A. Golovanov、V. V. Bekin、I. S. Odin、A. Yu. Chertov、O. B. Grigor’eva、V. S. Pisareva
DOI:10.1134/s1070428015120039
日期:2015.12
Nucleophilic addition of secondary heterocyclic amines (morpholine, piperidine, and piperazine) to the double or triple bond of (E)-1,5-diarylpent-2-en-4-yn-1-ones is controlled by the kinetic and thermodynamic factor, respectively. The regioselectivity of the addition of piperazine to these enynones is determined by the substituent nature in the benzene rings. Conjugated ketones with electron-donating
Synthesis of 1,5-disubstituted (E)-pent-2-en-4-yn-1-ones
作者:A. A. Golovanov、D. R. Latypova、V. V. Bekin、V. S. Pisareva、A. V. Vologzhanina、V. A. Dokichev
DOI:10.1134/s1070428013090030
日期:2013.9
The condensation of 3-arylpropynals with aryl methyl ketones in the presence of sodium hydroxide in 50% aqueous ethanol at 0A degrees C (Claisen-Schmidt reaction) afforded up to 89% of the corresponding (E)-1,5-diarylpent-2-en-4-yn-1-ones. The E configuration of the double C=C bond and cis conformation of the enone fragment in the products in crystal and CDCl3 solution were determined by X-ray analysis and H-1 NMR spectroscopy.
Nucleophilic sulfanylation of 1,5-disubstituted pent-2-en-4-yn-1-ones
作者:A. A. Golovanov、D. M. Gusev、A. V. Vologzhanina、V. V. Bekin、V. S. Pisareva
DOI:10.1134/s1070428014010035
日期:2014.1
Regioselectivity of nucleophilic addition of benzenethiols and phenylmethanethiol to 1,5-diarylpent-2-en-4-yn-1-ones in ethanol in the presence of triethylamine at 0-30A degrees C is determined by the nucleophile nature. Phenylmethanethiol adds to the double bond, whereas benzenethiols add to the triple bond. The addition products, 1,5-diaryl-3-benzylsulfanylpent-4-yn-1-ones and 1,5-diaryl-5-(4-arylsulfanyl)penta-2,4-dien-1-ones, respectively, were isolated in 43-89% yield. Substituents in the aryl rings of the substrates did not affect the reaction direction.