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51.
Etienne Brachet Prof. Jean‐Daniel Brion Dr. Mouad Alami Dr. Samir Messaoudi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(45):15276-15280
Unprotected thioglycosides were effective nucleophiles for Ni0‐catalyzed C? S bond‐forming reaction with functionalized (hetero)aryl, alkenyl, and alkynyl halides. The functional‐group tolerance on the electrophilic partner was typically high and the anomeric selectivities of the thioglycosides were high in all cases. The efficiency of this general procedure was well‐demonstrated by the synthesis of 4‐methyl‐7‐thioumbelliferyl‐β‐D ‐cellobioside (MUS‐CB). 相似文献
52.
Ahmed M. Metwaly Frank R. Fronczek Guoyi Ma Hazem A. Kadry Atef A. El-Hela Abd-Elsalam I. Mohammad Stephen J. Cutler Samir A. Ross 《Tetrahedron letters》2014
Four new (1–4) and two known (5 and 6) α-pyrone derivatives have been isolated from Alternaria phragmospora, an endophytic fungus from Vinca rosea, leaves. The isolated compounds were chemically identified to be 5-butyl-4-methoxy-6-methyl-2H-pyran-2-one (1), 5-butyl-6-(hydroxymethyl)-4-methoxy-2H-pyran-2-one (2), 5-(1-hydroxybutyl)-4-methoxy-6-methyl-2H-pyran-2-one (3), 4-methoxy-6-methyl-5-(3-oxobutyl)-2H-pyran-2-one (4), 5-(2-hydroxyethyl)-4-methoxy-6-methyl-2H-pyran-2-one (5), and 5-[(2E)-but-2-en-1-yl]-4-methoxy-6-methyl-2H-pyran-2-one (6). Compounds 2 and 4 showed moderate antileukemic activities against HL60 cells with IC50 values of 2.2 and 0.9 μM and against K562 cells with IC50 values of 4.5 and 1.5 μM, respectively. 相似文献
53.
Rongmei Si Dr. Li Wei Dr. Hong Wang Dingdian Su Prof. Samir H. Mushrif Prof. Yuan Chen 《化学:亚洲杂志》2014,9(3):868-877
Selective polymer wrapping is a promising approach to obtain high‐chiral‐purity single‐walled carbon nanotubes (SWCNTs) needed in technical applications and scientific studies. We showed that among three fluorene‐based polymers with different side‐chain lengths and backbones, poly[(9,9‐dihexylfluorenyl‐2,7‐diyl)‐co‐(9,10‐anthracene)] (PFH‐A) can selectively extract SWCNTs synthesized from the CoSO4/SiO2 catalyst, which results in enrichment of 78.3 % (9,8) and 12.2 % (9,7) nanotubes among all semiconducting species. These high‐chiral‐purity SWCNTs may find potential applications in electronics, optoelectronics, and photovoltaics. Furthermore, molecular dynamics simulations suggest that the extraction selectivity of PFH‐A relates to the bending and alignment of its alkyl chains and the twisting of its two aromatic backbone units (biphenyl and anthracene) relative to SWCNTs. The strong π–π interaction between polymers and SWCNTs would increase the extraction yield, but it is not beneficial for chiral selectivity. Our findings suggest that the matching between the curvature of SWCNTs and the flexibility of the polymer side chains and the aromatic backbone units is essential in designing novel polymers for selective extraction of (n,m) species. 相似文献
54.
Abdurrahman Turksoy Samir Bouayad-Gervais Prof. Franziska Schoenebeck 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(46):e202201435
While the N-trifluoromethylation of cyclic ureas is of interest for the potential to fundamentally change the properties of these biologically relevant moieties, the single synthetic procedure known to date describing their access only gives 4,4-disubstituted or fused aromatic cyclic N-CF3 urea derivatives. We herein report an alternative approach to unleash access to the 4-monosubstituted imidazolidinone motif. The strategy relies on straightforward cyclization of readily accessible acyclic ureas, enabled by Ag-catalysis or light-assisted proton coupled electron transfer. The cyclic core is shown to be highly robust and amenable to various derivatizations, such as tandem Ni-catalysis, C−B, C−N, C−C cross couplings or C−H functionalizations, tolerating basic, nucleophilic and/or oxidizing conditions. 相似文献
55.
Harech Mohamed Amine Dabbebi Rawia Abouliatim Younes Elhafiane Youssef Smith Agnès Mesnaoui Mohamed Niboue Lahbib Baklouti Samir 《Journal of Thermal Analysis and Calorimetry》2022,147(10):5677-5686
Journal of Thermal Analysis and Calorimetry - The aim of the present work is to characterize the phosphate sludge from two different countries: Morocco and Tunisia, and to study the difference... 相似文献
56.
José Carlos Velasco Calderón Shang Jiang Prof. Dr. Samir H. Mushrif 《Chemphyschem》2021,22(21):2222-2230
The addition of aprotic solvents results in higher reactivities and selectivities in many key aqueous phase biomass reactions, including the acid-catalyzed conversion of fructose to 5-hydroxyl methyl furfural (HMF). The addition of certain co-solvents inhibits the formation of humins via preferential solvation of key functional groups and can alter reaction kinetics. An important factor in this context is the relative stability of the hydronium ion (the catalyst) in the vicinity of the biomass moiety as compared to that in bulk, as it could determine its efficacy in the protonation step. Hence, in the present work, molecular dynamics (MD) simulations of HMF (the model product) and fructose (the model reactant) in acidic water and water-DMSO mixtures are performed to analyze their interaction with the hydronium ions. We show that the presence of DMSO favors the interaction of the hydronium ion with fructose, whereas it has a detrimental effect on the interaction of hydronium ion with HMF. Well-tempered metadynamics (WT-MTD) simulations are performed to determine the relative stability of the hydronium ion in the immediate vicinity of fructose and HMF, as compared to that in the bulk solvent phase, as a function of solvent composition. We find that DMSO improves the stabilization of the hydronium ions in the first solvation shell of fructose compared to that in the bulk solvent. On the other hand, hydronium ions become less stable in the immediate vicinity of HMF, as the concentration of DMSO increases. 相似文献
57.
Wahid M. Basyouni Samir Y. Abbas Khairy A. M. El-Bayouki Reham M. Dawood Mostafa K. El Awady Tawfeek H. Abdelhafez 《Journal of heterocyclic chemistry》2021,58(9):1766-1774
7-Chloro-2-(propylthio)thiazolo[5,4-d]pyrimidine 4 was prepared and used as a precursor for synthesizing new derivatives of thiazolo[5,4-d]pyrimidine through the nucleophilic displacement of the chlorine atom by different types of amino derivatives. Reaction of compound 4 with primary and secondary amines produced the corresponding substituted amino derivatives. Reaction of 4 with hydrazine hydrate then followed by condensation with aromatic aldehydes afforded hydrazone derivatives. Reaction of 4 with hydrazine hydrate then followed by reaction with isothiocyanates gave the disubstituted thiosemicarbazides. Finally, treatment of 4 with hydrazine derivatives afforded the novel disubstituted hydrazine derivatives. Preliminary antiviral screening on the bovine viral diarrhea virus (BVDV) was carried out, which was classified as a member of the same family of Hepatitis C virus. The results indicated that some of the tested compounds exhibited anti-BVDV activity which may be suitable for a new lead molecule to design more potent anti-BVDV agents. 相似文献
58.
Mohamed A. Salem Samir Y. Abbas Mohamed H. Helal Abdullah Y. Alzahrani 《Journal of heterocyclic chemistry》2021,58(11):2117-2123
As trail to overcome on the antimicrobial drug-resistance problems, new functionalized 2-pyridinone and 2-iminochromene derivatives bearing morpholine moiety were designed and synthesized. The 2-pyridinone derivatives were obtained through the cyclization of cyanoacetohydrazone of 4-morpholinylacetophenone with 1,3-dicarbonyl compounds, α,β-unsaturated nitriles or 2-(arylidene)malononitriles. The 2-iminochromene derivatives were synthesized through the ring closure of cyanoacetohydrazonewith salicylaldehyde derivatives. The antibacterial and antifungal activities for the synthesized 2-pyridinone and 2-iminochromene derivatives were investigated. Most of the tested compounds showed moderate activity against P. vulgaris. Compounds 4a,b and 5a,b showed moderate activity against G −ve bacteria. All iminochromene derivatives showed moderate activity against C. albicans. Compound 8c was the most active compound. 相似文献
59.
Kumar Samir Taneichi Taiga Fukuoka Takao Namura Kyoko Suzuki Motofumi 《Cellulose (London, England)》2021,28(17):10803-10813
Cellulose - Surface-enhanced Raman spectroscopy (SERS)-based biosensors have recently been extensively developed because of their high sensitivity and nondestructive nature. Conventional SERS... 相似文献
60.
Alshymaa Abdel-Rahman Gomaa Usama Ramadan Abdelmohsen Markus Krischke Martin J. Mueller Amira Samir Wanas 《Natural product research》2020,34(18):2612-2615
AbstractThe present study evaluates the chemical composition of Zinnia elegans and Gazania rigens based on their metabolomic profiles using liquid chromatography coupled with high-resolution mass spectrometry (LC‐HR-MS), alongside with the anti-infective activities of their ethanol extracts, as well as, different fractions. A significant difference was observed between the LC-MS profiles of the two plants such as, coumarins, sesquiterpene lactones and phenylethanoids which were characteristic for Z. elegans, while amides and phenolic acid derivatives were characteristic for G. rigens. These results highlight the chemical potential of Z. elegans and G. rigens. Furthermore, the ethyl acetate fraction of Z. elegans showed a significant antimalarial activity with IC50 values of 21.03 and 13.72?µg/mL against Plasmodium falciparum D6 and P. falciparum W2, respectively. 相似文献