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排序方式: 共有77条查询结果,搜索用时 15 毫秒
1.
Dolorès Edmont Yvon Buisson Philippe Treillard Christophe Plisson Jacques Chenault 《合成通讯》2013,43(2):217-225
A high yielding N-amination of quinolones at low temperature via the use of O-mesitylenesulfonylhydroxylamine is reported. 相似文献
2.
Dr. Alberto Palazzolo Dr. Timothée Naret Dr. Marion Daniel-Bertrand David-Alexandre Buisson Dr. Simon Tricard Dr. Philippe Lesot Dr. Yannick Coppel Dr. Bruno Chaudret Dr. Sophie Feuillastre Dr. Grégory Pieters 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(47):21065-21070
We report the dramatic impact of the addition of N-heterocyclic carbenes (NHCs) on the reactivity and selectivity of heterogeneous Ru catalysts in the context of C−H activation reactions. Using a simple and robust method, we prepared a series of new air-stable catalysts starting from commercially available Ru on carbon (Ru/C) and differently substituted NHCs. Associated with C−H deuteration processes, depending on Ru/C-NHC ratios, the chemical outcome can be controlled to a large extent. Indeed, tuning the reactivity of the Ru catalyst with NHC enabled: 1) increased chemoselectivity and the regioselectivity for the deuteration of alcohols in organic media; 2) the synthesis of fragile pharmaceutically relevant deuterated heterocycles (azine, purine) that are otherwise completely reduced using unmodified commercial catalysts; 3) the discovery of a novel reactivity for such heterogeneous Ru catalysts, namely the selective C-1 deuteration of aldehydes. 相似文献
3.
Dr. Viktor Pfeifer Marie Certiat Dr. Donia Bouzouita Dr. Alberto Palazzolo Sébastien Garcia-Argote Elodie Marcon David-Alexandre Buisson Dr. Philippe Lesot Prof. Laurent Maron Dr. Bruno Chaudret Dr. Simon Tricard Dr. Iker del Rosal Prof. Romuald Poteau Dr. Sophie Feuillastre Dr. Grégory Pieters 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(22):4988-4996
Ruthenium nanocatalysis can provide effective deuteration and tritiation of oxazole, imidazole, triazole and carbazole substructures in complex molecules using D2 or T2 gas as isotopic sources. Depending on the substructure considered, this approach does not only represent a significant step forward in practice, with notably higher isotope uptakes, a broader substrate scope and a higher solvent applicability compared to existing procedures, but also the unique way to label important heterocycles using hydrogen isotope exchange. In terms of applications, the high incorporation of deuterium atoms, allows the synthesis of internal standards for LC-MS quantification. Moreover, the efficacy of the catalyst permits, even under subatmospheric pressure of T2 gas, the preparation of complex radiolabeled drugs owning high molar activities. From a fundamental point of view, a detailed DFT-based mechanistic study identifying undisclosed key intermediates, allowed a deeper understanding of C−H (and N−H) activation processes occurring at the surface of metallic nanoclusters. 相似文献
4.
5.
Giovanelli E Leroux S Moisan L Carreyre H Thuéry P Buisson DA Meddour A Coustard JM Thibaudeau S Rousseau B Nicolas M Hellier P Doris E 《Organic letters》2011,13(15):4116-4119
Detailed investigations on one of the key steps of the superacidic fluorination of Vinca alkaloids that is the origin of C20' activation are reported. While two different pathways can be envisioned for the emergence of the transient secondary carbocationic intermediate, isotopic labeling experiments unambiguously revealed the involvement of a 1,2-hydride shift mechanism. 相似文献
6.
7.
Experimental results of acoustic paramagnetic resonance of Ti2+ in CaO are reported. The spectra are interpreted as due to Ti2+ ions in cubic sites distorted by random strains. The anisotropy comes from the fact that the effect of these strains is of the same order of magnitude as the Zeeman effect. The results are compared to those obtained with V3+ in MgO. 相似文献
8.
A.?Karout P.?Buisson A.?Perrard A.?C.?PierreEmail author 《Journal of Sol-Gel Science and Technology》2005,36(2):163-171
The synthesis of silica aerogels reinforced with either carbon or silica fibre felts and which encapsulate the lipase PS of Amano (LPS AB025407) obtained from Burkholderia cepacia is described. The materials were further shaped by moulding them in Teflon® tubes. The silica aerogels were synthesized with various ratios of hydrophobic groups and dried according to the supercritical CO2 method. Both types of reinforcements improve the catalytic activity of the material per mass of lipase. The fibre felts reinforcements also enable the encapsulation of higher concentrations of lipase. The materials were shaped into small moulded monoliths, which were readily washed and recycled without significant mechanical deterioration or loss of catalytic activity. In addition, hydrophobic carbon felts reinforce more efficiently silica aerogels that incorporate a high ratio of hydrophobic groups, while silica felts strengthen those aerogels that carry a low proportion of hydrophobic groups. 相似文献
9.
Alberto Palazzolo Sophie Feuillastre Viktor Pfeifer Sbastien Garcia‐Argote Donia Bouzouita Simon Tricard Cline Chollet Elodie Marcon David‐Alexandre Buisson Sophie Cholet Franois Fenaille Guy Lippens Bruno Chaudret Grgory Pieters 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(15):4945-4949
A general approach for the efficient hydrogen‐isotope exchange of nucleobase derivatives is described. Catalyzed by ruthenium nanoparticles, using mild reaction conditions, and involving either D2 or T2 as isotopic sources, this reaction possesses a wide substrate scope and a high solvent tolerability. This novel method facilitates the access to essential diagnostic tools in drug discovery and development: tritiated pharmaceuticals with high specific activities and deuterated oligonucleotides suitable for use as internal standards during LC‐MS quantification. 相似文献
10.
Joanie Otin N. Thuy Tran Aurélie Benoit Corinne Buisson Myriam Taverna 《Electrophoresis》2023,44(9-10):807-817
A capillary electrophoresis method is proposed to analyze the four most well-known growth hormone–releasing hormone (GHRH) analogs that are misused by athletes. Dimethyl-β-cyclodextrin used as a chiral selector allowed, for the first time, the separation of those basic peptide analogs, including enantiopeptides (sermorelin and CJC-1293) that differ by the chirality of only one amino acid. To increase the method sensitivity, electrokinetic preconcentration methods have been investigated. The large volume sample stacking with polarity switching (PS-LVSS) method with an injected sample volume corresponding to 80% of the capillary one was found superior to the sweeping in terms of signal enhancement factor (SEF). Acid and organic solvent addition to the sample (0.1 mM phosphoric acid with 30% methanol) led to a twofold signal improvement, when compared to water as a matrix. We increased capillary dimensions to provide a signal enhancement through the injection of a larger sample volume. Finally, using a combination of the optimized PS-LVSS preconcentration with the chiral capillary zone electrophoresis (CZE), the GHRH analogs were separated and limits of detection between 75 and 200 ng/mL were reached. This method was successfully applied to urine after a desalting step. An optimized C18 SPE was used for that purpose in order to provide low sample conductivity (<130 µS/cm) and preserve the efficiency of LVSS preconcentration. SEF of 640 was obtained with desalted urine spiked with sermorelin by comparison to the CZE (without preconcentration) method. 相似文献