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11.
Audisio D Messaoudi S Peyrat JF Brion JD Alami M 《The Journal of organic chemistry》2011,76(12):4995-5005
3-(N-Substituted) 4(1H)-quinolinones were synthesized using the copper-catalyzed Ullmann C-N bond forming strategy in moderate to quantitative yields. Starting from 3-halo-4(1H)-quinolones, various nucleophiles including amides, lactams, sulfonamides and NH-containing azoles have been used successfully. In all cases, the reactions take place rapidly in toluene and proceed by using copper powder as a catalyst, DMEDA as a ligand and K(2)CO(3) as a base. In addition, other related heterocycles such as 3-bromoquinolin-2(1H)-ones, 3-bromocoumarin, and 3,5-dibromo-2-pyridone show good to very high reactivity with various nucleophiles under our Cu/DMEDA catalyst system. 相似文献
12.
13.
Jean-Daniel Boissonnat David Cohen-Steiner Gert Vegter 《Discrete and Computational Geometry》2008,39(1-3):138-157
This paper addresses the problem of piecewise linear approximation of implicit surfaces. We first give a criterion ensuring
that the zero-set of a smooth function and the one of a piecewise linear approximation of it are isotopic. Then, we deduce
from this criterion an implicit surface meshing algorithm certifying that the output mesh is isotopic to the actual implicit
surface. This is the first algorithm achieving this goal in a provably correct way. 相似文献
14.
Anna Giusti Dr. Gaëlle Charron Dr. Sandra Mazerat Jean‐Daniel Compain Pierre Mialane Prof. Anne Dolbecq Dr. Eric Rivière Dr. Wolfgang Wernsdorfer Dr. Rosa Ngo Biboum Bineta Keita Dr. Louis Nadjo Prof. Arianna Filoramo Dr. Jean‐Philippe Bourgoin Dr. Talal Mallah Prof. 《Angewandte Chemie (International ed. in English)》2009,48(27):4949-4952
A POM to remember : Hexanuclear FeIII polyoxometalate (POM) single‐molecule magnets (see structure) can be noncovalently assembled on the surface of single‐wall carbon nanotubes. Complementary characterization techniques (see TEM image and magnetic hysteresis loops) demonstrate the integrity and bistability of the individual molecules, which could be used to construct single‐molecule memory devices.
15.
An efficient and practical decarboxylative cross-coupling reaction of quinolin-4(1H)-one 3-carboxylic acids with (hetero)aryl halides has been established. Under a bimetallic system of PdBr(2) and silver carbonate, the protocol proved to be general, and a variety of 3-(hetero)aryl 4-quinolinones and related heterocycles, such as 3-aryl-1,8-naphthyridin-4(1H)-ones, 3-arylcoumarins, 3-arylquinolin-2(1H)-ones, and 2-arylchromones, can be prepared in good to excellent yields. 相似文献
16.
Compain G Martin-Mingot A Frapper G Bachmann C Jouannetaud MP Thibaudeau S 《Chemical communications (Cambridge, England)》2012,48(47):5877-5879
Anti-Markovnikov additions to non-conjugated unsaturated amines in superacid are reported. In situ NMR studies, DFT calculations and labelled substrates reactions support the involvement of new ammonium-carbenium superelectrophiles in this original process. 相似文献
17.
Olivier Russo Abdallah Hamze Nathanäel Olivi Jean-Daniel Brion Sames Sicsic Isabelle Berque-Bestel Mouâd Alami 《Tetrahedron》2007,63(43):10671-10683
An efficient palladium-copper-catalyzed three-component assembling of propargyl halides, aryl or heteroaryl halides, and secondary amines is described. A wide variety of tertiary propargylic amines were synthesized in good to excellent yields from easily accessible starting materials. This three-component assembling was also effective when using potassium phthalimide or di-tert-butyliminodicarbonate instead of secondary amines. Consequently, it provides a quick entry to N-protected propargylic amines suitable intermediates for the synthesis of primary and secondary propargylic amines. In a similar way, related compounds including propargylic amide, carbamate and sulfonamide derivatives were efficiently obtained. This catalytic domino three-component process has been applied successfully to the construction of functionalized 2-(aminomethyl)benzo[b]furan or indole derivatives of biological interest. 相似文献
18.
Compain S Schlemmer D Levi M Pruvost A Goujard C Grassi J Benech H 《Journal of mass spectrometry : JMS》2005,40(1):9-18
Besides liquid chromatographic (LC)/UV methods adapted to therapeutic drug monitoring, there is still a need for more powerful techniques that can be used for pharmacological research and clinical purposes. We developed an LC method coupled with tandem mass spectrometry (MS/MS) to separate, detect and quantify with high sensitivity the nucleoside analogues used in multitherapies (zidovudine, stavudine, zalcitabine, didanosine, lamivudine and abacavir) in plasma and in the intracellular medium. We worked on two essential issues: (i) the need to use two ionization modes in order to achieve the best sensitivity, which leads to the optimization of the chromatographic separation of drugs detected in the positive ionization mode and drugs detected in the negative ionization mode, and (ii) the need to optimize the extraction step in order to enhance sample recovery. The peripheral blood mononuclear cells were lysed in Tris buffer-MeOH. A clean-up procedure was performed by solid-phase extraction only for plasma samples. The LC separation was carried out on a Zorbax Stable Bond C(18) column followed by MS/MS analysis after electrospray ionization in either the negative or positive mode. The positive ionization mode was applied at the beginning of the run to detect zalcitabine and lamivudine, then the ionization mode was changed to negative for the detection of didanosine, stavudine, internal standard and zidovudine. The calibration range for all the analytes was 0.5-200 ng ml(-1). The recoveries were between 64 and 90%, with coefficients of variation (CVs) lower than 15%. The inaccuracy (bias) was +/-15% with CVs always lower than 12%. The analytes were stable at room temperature and in the extraction solvent for at least 24 h, after storage at -80 degrees C for 3 months, after three freeze-thaw cycles and in the injection solvent after 48 h at 4 degrees C. Together with the measurement of intracellular triphosphorylated metabolites thanks to the powerful plasma and intracellular assay method for intact drugs, it is possible to describe the behaviour of nucleoside analogues against HIV through plasma pharmacokinetics, cell membrane diffusion including drug transport involvement, and also the intracellular metabolism. 相似文献
19.
The efficient synthesis of the iminoalditols derivatives 1 and 2 (nojirimycin alpha-C-glycosides) has been achieved in 10 steps from commercially available 2,3;4,6-di-O-isopropylidene-alpha-L-sorbofuranose in an overall yield of 23-27%. 相似文献
20.
The activation of α-amino C-H bonds in azacycloalkanes by way of intramolecular rhodium-catalyzed amination is reported. In this study, the ‘activating’ sulfamoyloxy group is attached to the endocyclic nitrogen atom with an appropriate linker. The influence of various structural parameters was studied. Results obtained demonstrate the remarkable conformational control that is possible with such azacycloalkane systems. This work leads to the first example of a successful intramolecular catalyzed amination of a tertiary sulfamic ester, a substrate known to be highly prone to elimination and/or nucleophilic displacement. 相似文献