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1.
Arylazides reacted with α amino-acrylonitriles to produce 1-aryl-5-amino-triazoles, and with β amino-acrylonitriles to give 1-aryl-4-cyanotriazoles. Kinetics showed the Hammett ρ to be > o and therefore, these reactions are controlled by LUMOazide-HOMOolefin interaction. Despite the captodative substitution in and (ΔΔ E≠~ 500 cal.M?1) does'nt agree with a diradical intermediate. 相似文献
2.
S. Bellahouel E. Belhadj H. Sekkiou R. Hamacha N. Kambouche A. Derdour A. Bengueddach 《Arabian Journal of Chemistry》2011,4(3):355-359
The condensation of sugar with fatty acids in an organic media is possible by chemical amidification without fastidious steps by hydroxyl group protection/deprotection. The acylation of sugar (N-methyl glucamine) with fatty acids (lauric acid, palmitic acid and stearic acid) is catalyzed in the presence of two inorganic and acid solid catalysts: Algerian clay called bentonite of Maghnia and mesoporous material of type (Al–MCM-41). The results obtained with this last solid (i.e. MCM-41) are very encouraging. 相似文献
3.
The 1,3-dipolar cycloaddition of nitrile oxides to 1-cyanoenamines gives 5-aminoisoxazoles regioselectively. Moderate to good yields could be obtained depending on the method used to generate the nitrile oxides. The intermediate isoxazolines could not be isolated. 相似文献
4.
The synthesis of a new type of liquid crystalline compound derived from 1,2,3-triazole was achieved using Wittig reaction. Polarised microscopy studies, X-ray scattering and differential scanning calorimetry analysis revealed that the target compounds exhibit enantiotropic liquid crystalline properties. Their mesomorphic behaviour is closely related to the nature of substituents in position N1 of the heterocycle, the length of the mesogenic core as well as the isomerisation nature (E/Z) of the double bond. 相似文献
5.
A. Parisini D. Nobili A. Armigliato M. Derdour L. Moro S. Solmi 《Applied Physics A: Materials Science & Processing》1992,54(3):221-224
The thermal evolution of monoclinic SiAs precipitates at 1050° C in silicon samples implanted with 1 and 1.5×1017 As/cm2 was followed by transmission electron microscopy (TEM) and secondary neutral mass spectrometry (SNMS). These experiments show, for the first time, the coexistence of two different states of As in silicon, i.e., the electrically active and the inactive mobile dopant, in equilibrium with monoclinic SiAs precipitates. Moreover, they provide, for the saturation concentration of As in silicon, which includes both these states, a value of 3×1021 cm–3 at 1050° C. 相似文献
6.
Zeghada S Bentabed-Ababsa G Derdour A Abdelmounim S Domingo LR Sáez JA Roisnel T Nassar E Mongin F 《Organic & biomolecular chemistry》2011,9(11):4295-4305
Reactions were performed from aryl azides on the one hand, and activated alkenes coming from β-dicarbonyl compounds or malonodinitrile on the other hand, either with recourse to conventional heating or to microwave activation, to afford 1-aryl-1H-1,2,3-triazoles. The mechanism and the regioselectivity of the reactions involving β-dicarbonyl compounds have been theoretically studied using DFT methods at the B3LYP/6-31G* level: they are domino processes comprising a tautomeric equilibrium of the β-dicarbonyl compounds with their enol forms, a 1,3-dipolar cycloaddition of the enol forms with the aryl azides (high activation energy), and a dehydration process (lower activation energy). The effect of non-conventional activation methods on the degradation of 1,2,3-triazolines was next studied experimentally. Finally, some of the 1,2,3-triazoles such synthesized were evaluated for their bactericidal and cytotoxic activities. 相似文献
7.
L'Helgoual'ch JM Bentabed-Ababsa G Chevallier F Yonehara M Uchiyama M Derdour A Mongin F 《Chemical communications (Cambridge, England)》2008,(42):5375-5377
This communication describes the deproto-metalation of a large range of aromatics including heterocycles using a newly developed lithium-cadmium base; the reaction proceeds at room temperature with an excellent chemoselectivity and efficiency, and proved to be regioselective in most cases. 相似文献
8.
Bentabed-Ababsa G Derdour A Roisnel T Sáez JA Domingo LR Mongin F 《Organic & biomolecular chemistry》2008,6(17):3144-3157
The [3 + 2] cycloaddition reaction between carbonyl ylides generated from epoxides and ketones (ethyl pyruvate, ethyl phenylglyoxylate, isatin, N-methylisatin and 5-chloroisatin) to give substituted dioxolanes and spirocyclic dioxolane indolinones was investigated. The effect of microwave irradiation on the outcome of the reaction was studied. The thermal reaction between 2,2-dicyano-3-phenyloxirane and N-methylisatin was theoretically studied using DFT methods. This reaction is a domino process that comprises two steps. The first is the thermal ring opening of the epoxide to yield a carbonyl ylide intermediate, whereas the second step is a polar [3 + 2] cycloaddition to yield the final spiro cycloadducts. The cycloaddition presents a low stereoselectivity and a large regio- and chemoselectivity. Analysis of the electrophilicity values and the Fukui functions of the reagents involved in the cycloaddition step allowed the chemical outcome to be explained. 相似文献
9.
Chahinez Benbayer Salima Saidi-Besbes Elisabeth Taffin de Givenchy Sonia Amigoni Frédéric Guittard Aicha Derdour 《Colloid and polymer science》2014,292(7):1711-1717
The radical copolymerization of three polymerizable surfactants with styrene was investigated by NMR spectroscopy to assess their compositions. The reactivity ratios of these monomers were calculated according to the methods of Fineman–Ross and Kelen–Tüdos. Consequently, Q and e values were deduced by the Alfrey and Price method. The results indicated the positive effect of the fluorine chain on the reactivity of monomers bearing a long spacer between the ammonium head and the acrylic function. These monomers exhibit high e values which are in favor of an intramolecular conformation of the surfactant where the ester carbonyl function of the polymerizable group interacts with the onium nitrogen atom via a compact six-sided structure. 相似文献
10.
Dahane Soraya Gil García María Dolores Uclés Moreno Ana Martínez Galera María Socías Viciana María del Mar Derdour Aicha 《Mikrochimica acta》2015,182(1-2):95-103
Microchimica Acta - We describe a MWCNT-based method for the solid-phase extraction of eight pesticides from environmental water samples. The analytes are extracted from 100 mL samples at... 相似文献