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61.
Dissolution of Cellulose and Lignin with Biobased Ionic Liquids 总被引:1,自引:0,他引:1
Mbakidi Jean-Pierre Kerkache Asma Lazar Florica Bouquillon Sandrine 《Journal of solution chemistry》2022,51(3):345-356
Journal of Solution Chemistry - Choline-based ionic liquids, involving various alkyl chains lengths and carboxylates derived from biobased acids, have been synthetized with high yields through a... 相似文献
62.
63.
Guillaume Lafitte Audrey Beillard Sandrine Chambon Catherine Soulet Laurence Dumais Grégoire Mouis Jean-François Fournier Laurence Clary Claire Bouix-Peter Loic Tomas Craig S. Harris 《Tetrahedron letters》2018,59(3):256-259
During our search for novel CGRP antagonists, we had great difficulty in accessing one of our key motifs. Herein, we communicate how we solved the problem by an unprecedented Mitsunobu alkylation using unprotected amino alcohols. 相似文献
64.
Glycosyl‐Substituted Dicarboxylates as Detergents for the Extraction,Overstabilization, and Crystallization of Membrane Proteins 下载免费PDF全文
Dr. Kim‐Anh Nguyen Dr. Marine Peuchmaur Sandrine Magnard Dr. Romain Haudecoeur Dr. Cédric Boyère Saravanan Mounien Ikram Benammar Veronica Zampieri Dr. Sébastien Igonet Dr. Vincent Chaptal Dr. Anass Jawhari Prof. Ahcène Boumendjel Dr. Pierre Falson 《Angewandte Chemie (International ed. in English)》2018,57(11):2948-2952
To tackle the problems associated with membrane protein (MP) instability in detergent solutions, we designed a series of glycosyl‐substituted dicarboxylate detergents (DCODs) in which we optimized the polar head to clamp the membrane domain by including, on one side, two carboxyl groups that form salt bridges with basic residues abundant at the membrane–cytoplasm interface of MPs and, on the other side, a sugar to form hydrogen bonds. Upon extraction, the DCODs 8 b , 8 c , and 9 b preserved the ATPase function of BmrA, an ATP‐binding cassette pump, much more efficiently than reference or recently designed detergents. The DCODs 8 a , 8 b , 8 f , 9 a , and 9 b induced thermal shifts of 20 to 29 °C for BmrA and of 13 to 21 °C for the native version of the G‐protein‐coupled adenosine receptor A2AR. Compounds 8 f and 8 g improved the diffraction resolution of BmrA crystals from 6 to 4 Å. DCODs are therefore considered to be promising and powerful tools for the structural biology of MPs. 相似文献
65.
Following the isolation from marine sponges, in 1993, of a family of related highly oxygenated macrolactones named spongistatins, altohyrtins and cinachyrolides, impressive synthetic efforts have been devoted to the synthesis of these macrolides. Their highly potent activity as cancer cells growth inhibitors combined with a fascinating and complex architecture has prompted synthetic organic chemists to develop efficient routes to these molecules. From the first total syntheses by the groups of Evans and Kishi in 1997 and 1998 which delivered milligram quantities of spongistatins/altohyrtins, further intensive studies have led to new pathways with practical solution to provide gram scale amounts of key intermediates. The present review focuses on biological properties and synthetic issues related to these marine macrolides. 相似文献
66.
Gruber-Woelfler H Rivillon Amy S Chabal YJ Schitter G Polo E Ringwald M Khinast JG 《Chemical communications (Cambridge, England)》2008,(11):1329-1331
A tethered ethylenebis(indenyl) zirconocene was covalently immobilized on H-terminated Si(111) surfaces using UV-mediated alkene hydrosilylation, thus making possible the development of structured catalytic surfaces with highly controlled properties. 相似文献
67.
Many natural products of biological interest contain [6,5]- and [6,6]-spiroketal moieties that can adopt various configurations, benefiting or not from anomeric conformation stabilizing effects. The spiroketal fragments are often important for the biological activity of the compounds containing them. Most stable spiroketal stereoisomers, including those benefiting from conformational anomeric effects (gauche conformers can be more stable than anti conformers because of a contra-steric stabilizing effect), are obtained easily under acidic conditions that permit acetal heterolysis (formation of tertiary oxycarbenium ion intermediates). The synthesis of less stable stereoisomers requires stereoselective acetal forming reactions that do not permit their equilibration with their most stable stereoisomers or, in the case of suitably substituted derivatives, concomitant reactions generating tricyclic products that quench the less stable spiroketal conformers. Ingenuous approaches have been recently developed for the synthesis of naturally occurring [6,6]- and [5,6]-nonanomeric spiroketals and analogues. The identification of several parameters that can influence the stereochemical outcome of spirocyclization processes has led to seminal improvements in the selective preparation of the non-anomeric isomers that are discussed herein. This review also gives an up-dated view of conformational anomeric effect which represents a small fraction of the enthalpic anomeric effect that makes gem-dioxy substituted compounds much more stable that their 1,n-dioxy substituted isomers (n > 1). Although models assuming sp3-hybridized oxygen atoms have been very popular (rabbit ears for the two non-bonding electron pairs of oxygen atom), sp2-hybridized oxygen atoms are used to describe the conformational anomeric effect. 相似文献
68.
Jean-Florent Lamarque Sandrine Lassara Jérome Molette Stéphane Pellet-Rostaing Etsuji Okada Guillaume Pilet 《Journal of fluorine chemistry》2008,129(9):788-798
The synthesis of N-(2-trifluoroacetylaryl)propargylamines 10-14 and 17 is presented. The copper(I) catalyzed cycloaddition reaction of these propargylamines (dipolarophiles) with a series of azides (1,3-dipoles) 18-20, 21 and 24 was found to proceed smoothly in dimethylsulfoxide at room temperature, to furnish the corresponding 1,4-disubstituted-[1,2,3]triazole derivatives 26-36 in moderate to good yields. 相似文献
69.
Besselièvre F Mahuteau-Betzer F Grierson DS Piguel S 《The Journal of organic chemistry》2008,73(8):3278-3280
An efficient microwave-assisted palladium/copper co-mediated direct arylation of oxazoles with aryl bromides under ligandless conditions has been developed. The method is functional group tolerant and provides rapid access to medicinally relevant compounds in good yields. Coupled to the van Leusen oxazole ring synthesis, this methodology is illustrated by an expedient two-step synthesis of the four 2,5-diaryloxazole alkaloids texamine, texaline, balsoxin, and O-Me-halfordinol from commercially available starting materials. 相似文献
70.
Llewellyn PL Maurin G Devic T Loera-Serna S Rosenbach N Serre C Bourrelly S Horcajada P Filinchuk Y Férey G 《Journal of the American Chemical Society》2008,130(38):12808-12814
The adsorption of C1 to C4 linear hydrocarbons in the flexible metal organic framework MIL-53(Cr) has been followed by adsorption manometry coupled with microcalorimetry and Synchrotron X-ray powder diffraction. This experimental investigation was completed by molecular modeling. In the case of methane, the solid remains rigid whatever the adsorbate amount. However for the C2-C4 series, an increasing flexibility of the structure is observed, which is ascribed first to a breathing of the material from a large pore to a narrow pore form followed by a further expansion at high pressure. The collected thermodynamic and structural information suggests that a minimum adsorption enthalpy of ca. 20 kJ mol (-1) in the initial large pore structure of MIL-53(Cr) is required to induce the structural transition "large to narrow pore". Further, the enthalpy of adsorption can be used to predict the pressure at which the structure reopens. Finally, the magnitude of the breathing can be related to the size of the probe molecule via the van der Waals volume. The above trends have been successfully verified in the case of water and carbon dioxide. This combined experimental and theoretical approach gives the first elements for the prediction of whether or not the MIL53 and similar flexible structures will respond to gas loading and what would be the pressure required and further the amplitude of the induced breathing. 相似文献