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Malika Ibrahim-Ouali 《Tetrahedron letters》2009,50(14):1607-3676
The first total synthesis of 11-selena steroids was achieved via an intramolecular Diels-Alder cycloaddition of o-quinodimethanes as the key step. 相似文献
133.
K. Nahdi M. Férid Malika Trabelsi Ayadi 《Journal of Thermal Analysis and Calorimetry》2009,96(2):455-461
The aim of this work is to highlight the importance of controlling the residual water vapour pressure above the sample as
well as the rate of the thermal decomposition during the thermal dehydration of cerium cyclotriphosphate trihydrate CeP3O9·3H2O.
For this reason, the dehydration of the titled compound was followed by both techniques: the constant rate thermal analysis
at P
H2O = 5 hPa and the conventional TG-DTA in air. 相似文献
134.
Walton JC Brahmi MM Monot J Fensterbank L Malacria M Curran DP Lacôte E 《Journal of the American Chemical Society》2011,133(26):10312-10321
Fifteen second-generation NHC-ligated boranes with aryl and alkyl substituents on boron were prepared, and their radical chemistry was explored by electron paramagnetic resonance (EPR) spectroscopy and calculations. Hydrogen atom abstraction from NHC-BH(2)Ar groups produced boryl radicals akin to diphenylmethyl with spin extensively delocalized across the NHC, BH, and aryl units. All of the NHC-B·HAr radicals studied abstracted Br-atoms from alkyl bromides. Radicals with bulky N,N'-dipp substituents underwent dimerization about 2 orders of magnitude more slowly than first-generation NHC-ligated trihydroborates. The evidence favored head-to-head coupling yielding ligated diboranes. The first ligated diboranyl radical, with a structure intermediate between that of ligated diboranes and diborenes, was spectroscopically characterized during photolysis of di-t-butyl peroxide with N,N'-di-t-butyl-imidazol-2-ylidene phenylborane. The reactive site of B-alkyl-substituted NHC-boranes switched from the boron center to the alkyl substituent for both linear and branched alkyl groups. The β-borylalkyl radicals obtained from N,N'-dipp-substituted boranes underwent exothermic β-scissions with production of dipp-Imd-BH(2)· radicals and alkenes. The reverse additions of NHC-boryl radicals to alkenes are probably endothermic for alkyl-substituted alkenes, but exothermic for conjugated alkenes (addition of an NHC-boryl radical to 1,1-diphenylethene was observed). A cyclopropylboryl radical was observed, but, unlike other α-cyclopropyl-substituted radicals, this showed no propensity for ring-opening. 相似文献
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Malika Lahiani-Skiba Aude Coquard Fréderic Bounoure Philippe Vérité Philippe Arnaud Mohamed Skiba 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):197-201
Mebendazole is an antihelmintic drug, active against many intestinal parasites. Its systemic efficacy is limited by its poor
water solubility. The use of natural or derivatized cyclodextrins permeated to multiply notably its apparent solubility, especially
with permethyl β-cyclodextrine (PM β-CD) (multiplied by 4700). The inclusion complex formation between mebendazole and this
methylated β-cyclodextrin, was characterized by mass spectrometry, powder X-ray diffractometry and Fourier transform infrared
spectroscopy: mebendazole seemed to be included in permethyl β-cyclodextrin by its aromatic rings. To prepare inclusion complex
of mebendazole and PMβ-CD by solvent evaporation, acetone may be used and the ratio using lower amount of cyclodextrin (MBZ:CD,
1:2) should be used. 相似文献
138.
Dalila Ben Hassen-Chehimi Najia Kbir-Ariguib Malika Trabelsi-Ayedi 《Journal of Thermal Analysis and Calorimetry》1998,53(1):169-176
The isothermal section at 10°C of the solubility diagram of the ternary system Na+, Mg++// ClH2O was established by conductimetric and analytical measurements.
Two solid phases, NaCl and MgCl2·6H2O are observed. The solubility range of NaCl is large, while the liquidus curve of MgCl2·6H2O is very short.
The composition of the eutonic point, determined by two methods was: 0.32 g% NaCl and 33.80 g% MgCl2.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
139.
Houari Benamar Elonge Rarivoson Lamberto Tomassini Claudio Frezza Abderrazak Marouf Malika Bennaceur 《Natural product research》2019,33(10):1456-1462
In this work, the extracts obtained with different solvents from the leaves of Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire were studied for their phytochemical profile and then for their antioxidant and acetylcholinesterase inhibitory activities. The phytochemical profiles of the extracts in n-hexane, dichloromethane, ethyl acetate, methanol, anthraquinone rich and water, showed the presence of different compounds belonging to several classes of natural products such as flavonoids, anthraquinones, saccharides and fatty acids. For what concerns the biological tests, the ethyl acetate, methanol and anthraquinone rich extracts showed the highest activities in both assays due to the high amount of compounds possessing those properties such as flavonoids and anthraquinones. By consequence, these specific extracts of the species may be considered to be potential sources of natural antioxidant and anti-acetylcholinesterasic compounds. 相似文献
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