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111.
112.
Cover Picture: Fast‐Geomimicking using Chemistry in Supercritical Water (Angew. Chem. Int. Ed. 34/2016)
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113.
Moisan S Martinez V Weisbecker P Cansell F Mecking S Aymonier C 《Journal of the American Chemical Society》2007,129(34):10602-10606
We report in this paper novel chemistry that addresses the problem of surfactant solubility in supercritical CO2 for metal nanoparticle synthesis. This new approach for the preparation of organic-functionalized inorganic nanoparticles relies on the reduction of a metal precursor in a CO2-containing insoluble polymer. Reduction of the metal with H2 leads to small nanocrystals stabilized by the polymer with a relatively small polydispersity. The functionalized metal nanoparticles are recovered as a dry powder, free of any organic solvents, which can then be resuspended in an appropriate solvent. This approach limits the number of steps for the preparation of functional nanoparticles which are ready for use. To illustrate this, we report results of the preparation of palladium and silver nanoparticles of 3-5 nm size stabilized with hyperbranched polyamines, functionalized with perfluoroalkyl, perfluorooligoether, non-fluorinated alkyl, polysiloxane, or polyethylene glycol moieties. 相似文献
114.
The nature of the 7-substituent has a remarkable effect on the diastereoselectivity of the oxidative rearrangement of indole-2-carboxamides derived from (S)-2-methoxymethylpyrrolidine into chiral 3,3-disubstituted oxindoles. 相似文献
115.
We describe the first effective H/D exchange reaction with acidic substrates in CDCl(3) at room temperature. The particularly mild reaction conditions involved (solvent, base, and temperature) allow the chemoselective deuteration of ketones over esters. An NMR study was conducted with the aim of rationalizing the results obtained in the presence of TBD as catalyst. 相似文献
116.
117.
Lafon C Murillo-Rincon A Goldenstedt C Chapelon JY Mithieux F Owen NR Cathignol D 《Ultrasonics》2009,49(2):172-178
Miniature flat ultrasound transducers have shown to be effective for a large variety of thermal therapies, but the associated superficial heating implicates developing original strategies in order to extend therapeutic depth. The goal of the present paper is to use ultrasound contrast agents (UCA) to increase remote attenuation and heating. Theoretical simulations demonstrated that increasing attenuation from 0.27 to 0.8 Np/cm at 10 MHz beyond a distance of 18 mm from the transducer should result in longer thermal damages due to protein coagulation in a tissue mimicking phantom. Contrast agents (BR14, Bracco, Plan-les-Ouates, Switzerland) were embedded in thermo-sensitive gel and attenuations ranging from 0.27 to 1.33 Np/cm were measured at 10 MHz for concentrations of BR14 between 0 and 4.8%. Thermal damages were then induced in several gels, which had different layering configurations. Thermal damages, 12.8 mm in length, were obtained in homogeneous gels. When mixing contrast agents at a concentration of 3.2% beyond a first 18 mm-thick layer of homogeneous gel, the thermal damages reached 21.5 mm in length. This work demonstrated that contrast agents can be used for increasing attenuation remotely and extending therapeutic depth induced by a non-focused transducer. Additional work must be done in vivo in order to verify the remote-only distribution of bubbles and associated increase in attenuation. 相似文献
118.
A series of 4,4-difluoroisofagomine analogues were synthesized. These compounds were tested for inhibition of eight glycosidases. The 3R,5R isomer 1 is a new and potent inhibitor against β-glucosidase from almonds with Ki value of 1.2 μM. The influence of the gem-difluoromethylene group (CF2) on binding to glycosidases is discussed. It is concluded that only non-essential hydroxyl groups can be replaced by the gem-difluoro group and that in such a case (β-glycosidase) the change in inhibition is, interestingly, a result of the change in base strength. 相似文献
119.
The reactivity of tosylated glycerol carbonate 2 toward nucleophiles has been exploited to generate glycidol analogues protected with carbonate or carbamate groups. The activated glycerol 2 is a reasonable linking agent with thiol and alcohol nucleophiles and an excellent and selective one with primary amines, allowing efficient bis-functionalizations of glycerol. 相似文献
120.
Julien Coulomb Victor Certal Dr. Marie‐Hélène Larraufie Cyril Ollivier Dr. Jean‐Pierre Corbet Dr. Gérard Mignani Dr. Louis Fensterbank Prof. Emmanuel Lacôte Dr. Max Malacria Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(39):10225-10232
A general and efficient method for the synthesis of cyclic sulfinates and sulfinamides based on intramolecular homolytic substitution (SHi) at the sulfur atom by aryl or alkyl radicals is described. Both alkyl and benzofused compounds can be accessed directly from easily prepared acyclic precursors. Enantiomerically enriched sulfur‐based heterocycles were formed through an SHi process with inversion of configuration at the sulfur atom. Cyclization of prochiral radicals proceeded with varying stereochemical outcomes, depending on the size of the incoming radical. 2‐Pyridyl and 2‐quinolyl radicals led to biaryl compounds, which result from attack onto the ortho position of the arylsulfinate rather than a thiophilic substitution. 相似文献