查看更多>>摘要：An efficient cascade reaction has been developed to synthesize a series of 1,3-diols and 1,3,5-triols via reactions of arylalkynyl Grignard reagents with enol esters. The stereoselectivity of reactions and the molecular configurations of the products were confirmed by nuclear magnetic resonance, X-ray diffraction, and high-performance liquid chromatography analysis. A possible reaction mechanism was analyzed with the results indicating that it proceeded through a 1,2-addition/rearrangement and reverse O-acylation to produce the 1,3-diol and via C-acylation to form the 1,3,5-triol.
查看更多>>摘要：An aerobic oxidative bromination of anilines and aryl ketones catalyzed by recyclable 2-methylpyridinium nitrate ionic liquid is achieved in water using hydrobromic acid as the bromine source and molecular oxygen as the oxidant. The catalytic system shows good efficiency and atom economy.
Yengoyan, Aleksandr P.Shainova, Roza S.Gomktsyan, Tiruhi A.Karapetyan, Armen, V...
6页
查看更多>>摘要：The affordable and efficient methods for the syntheses of acyclic derivatives of 2-(3-(3,5-dimethyl-1H-pyrazol-1-yl)-6-oxopyridazin-1(6H)-yl)acetohydrazine as well as compounds with a combination of pyrazolyl-pyridazine fragment with various azoles in the molecules have been developed. The synthesized compounds showed a stimulating action on plant growth.
Oyebamiji, Abel KolawoleFadare, Olatomide A.Semire, Banjo
4页
查看更多>>摘要：Anti-gastric cancer activity of 18 synthesized compounds was studied using theoretical and computational method. The studied compounds were docked against mesenchymal-epithelial transition factor (PDB ID: 2wgj) and the obtained scoring was compared with the standard used. Thus, all the studied compounds were efficient than the standard (5-florouracil); also, A9 proved to be more effective than other studied compounds.
查看更多>>摘要：Hemslecin C, a compound with a novel skeleton, is synthesized by refluxing hemslecin A with KOH in alcohol. Hemslecin C was structurally characterized by specific optical rotation measurement, high-resolution mass spectroscopy, and nuclear magnetic resonance spectroscopic analysis. In addition, the molecular structure of hemslecin C was unambiguously determined by X-ray single-crystal determination. We found that its structure was different from that reported in the literature. The acetyl group of hemslecin A is transferred to the carbonyl alpha carbon of the side chain and is attacked by the 22-hydroxyl group to give a hemi-acetal that is dehydrated to give hemslecin C. The anticancer activity of this new skeleton is determined by sulforhodamine B assay method, and demonstrates excellent activity, thus providing a new framework for the development of anticancer drugs.
查看更多>>摘要：The vascular endothelial growth factor receptor-2 signaling pathway promotes the formation of new blood vessels, and vascular endothelial growth factor receptor-2 tyrosine kinase exists in both active and inactive conformations. Novel indole-benzimidazole and indole-benzothiazole derivatives joined by different linkers are designed and synthesized as inhibitors of vascular endothelial growth factor receptor-2 tyrosine kinase. All the synthesized compounds were evaluated for their cytotoxicity against four human cancer cell lines (HeLa, HT29, A549, and MDA-MB-435) and human umbilical vein endothelial cell. Meanwhile, the inhibitory activities against vascular endothelial growth factor receptor-2 are estimated in vitro and the binding interactions with dual conformations of vascular endothelial growth factor receptor-2 tyrosine kinase are evaluated by molecular docking. Compounds 5a-c and 14 show inhibitory activity against vascular endothelial growth factor receptor-2 tyrosine kinase and promising cytotoxicity, specifically with IC50 values ranging between 0.1 and 1 mu M, which imply broad-spectrum antitumor activity. These results provide a deep insight into potential structural modifications for developing potent vascular endothelial growth factor receptor-2 tyrosine kinase inhibitors.
查看更多>>摘要：The kinetics and mechanism of the osmium(VIII)-catalysed oxidation of crotyl alcohol by hexacyanoferrate(III) in aqueous alkaline medium is studied. The role of the osmium(VIII) catalyst is delineated to account for the experimental observations. A plausible reaction mechanism is suggested. Activation parameters such as the energy and entropy of activation are evaluated by employing the Eyring equation and are found to be 36.833 kJ mol(-1) and -141.518 J K-1 mol(-1), respectively.
查看更多>>摘要：For the first time, using PCl3, a range of tert-butyl esters is chlorinated successfully, allowing access of both aromatic acid chlorides and aliphatic acid chlorides in good yields. The method features simple reaction conditions and wide substrate scope. Various tert-butyl esters including aryl esters, alkenyl esters, and alkyl esters were tolerated well in the reaction. A plausible mechanism is proposed.
Ramirez, HegiraRodrigues, Juan R.Mijares, Michael R.De Sanctis, Juan B....
10页
查看更多>>摘要：A novel series of 2-[2-(7-chloroquinolin-4-ylthio)-4-methylthiazol-5-yl]-N-phenylacetamide derivatives is synthesized via substitution with 2-mercapto-4-methyl-5-thiazoleacetic acid at position 4 of 4,7-dichloroquinoline to obtain an intermediate acetic acid derivative. The chemical behavior of these reactants was investigated using different reaction conditions to optimize the nucleophilic substitution at position 4. The final compounds are prepared using a modified version of the Steglich esterification reaction between the acetic acid intermediate 3 and different anilines. The structures are confirmed by infrared, 1H, 13C, distortionless enhancement by polarization transfer 135 degrees, Correlated Spectroscopy, heteronuclear correlation spectroscopy and (Long range HETCOR using three BIRD pulses) FLOCK-NMR spectral studies, and by elemental analysis. The synthesized compounds are tested in vitro and in vivo for their potential antimalarial and anticancer activities, with derivative 11 being the most promising candidate.
查看更多>>摘要：A series of 1,3,4-oxadiazole-fused and piperazine-fused quinazoline derivatives is synthesized and evaluated as antibacterial agents. The synthetic protocol involves an efficient Suzuki C-C cross-coupling reaction on the quinazoline ring followed by formation of 1,3,4-oxadiazole intermediates. These are further treated with piperazine bases in the presence of formalin in methanol to furnish the final N-Mannich products. The majority of these compounds show potent antibacterial activities against several different strains of Gram-positive bacteria including multidrug-resistant clinical isolates. The cytotoxic activity assay demonstrates that the synthesized compounds do not affect cell viability on Human cervical (HeLa) cells at their minimum inhibitory concentrations. The newly synthesized compounds are characterized by infrared spectroscopy, H-1 NMR, C-13 NMR, mass spectrometry, and elemental analysis.
NSTL
Sage