- Styrylheterocycles as a novel class inhibitor of cyclooxygenase-2-mediated prostaglandin E2 production
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The inhibitory effects of a series of styrylheterocycles on the production of cyclooxygenase-2-mediated prostaglandin E2 (PGE2) were evaluated in lipopolysaccharide-stimulated RAW264.7 murine macrophages. A new series of potential inhibitors, including 3-[2-(4-methoxy-phenyl)-vinyl]- thiophene, have been identified, thus providing novel chemical leads for the further development of potential inhibitors in this capacity. The suppression of COX-2 mRNA expression by the active styrylheterocycles, in part, was involved in the inhibitory activity against the overproduction of PGE2.
- Lee, Sang Kook,Park, Eun-Jung,Lee, Eunjung,Min, Hye-Young,Kim, Eun-Young,Lee, Taeho,Kim, Sanghee
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- Stereospecific Iron-Catalyzed Carbon (sp2)-Carbon (sp2) Cross-Coupling of Aryllithium with Vinyl Halides
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We present herein an efficient synthetic protocol involving iron-catalyzed cross-coupling of organolithium compounds with vinyl halides as key coupling partners. More than 30 examples were obtained with moderate to good yields and high stereoselectivities. The practicality of this method is evidenced by a gram-scale synthesis. In addition, a preliminary mechanistic investigation was also performed.
- Chen, Peng,Peng, Xiao-Shui,Wang, Zhi-Yong,Wong, Henry N. C.
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supporting information
p. 4385 - 4390
(2021/06/27)
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- Determining the excited-state substituent constants of furyl and thienyl groups
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Six series of styrene derivatives XCH═CHArY (total of 65) containing the styrene parent molecular skeleton were synthesized (here, Y is OMe, Me, H, F, Cl, CF3, CN, and NO2, and X is 2-furyl, 3-furyl, 2′-methyl-2-furyl, 2-thienyl, 3-thienyl, and 2′-methyl-2-theniyl). Their ultraviolet absorption spectra were measured in anhydrous ethanol, and their wavelength of absorption maximum λmax was recorded. For the wavenumber νmax (cm?1, νmax?=?1/λmax) of the obtained λmax, a quantitative correlation analysis was performed, and 6 excited-state substituent constants σexcc(p) of groups X were obtained by means of curve-fitting method. Taking the νmax values of total 90 compounds of styrene derivatives as a data set (including 25 compounds from reference and 65 compounds of this work), a quantitative correlation analysis was performed, and the reliability of the obtained σexcc(p) was verified. In addition, 12 samples of disubstituted Schiff bases (XCH═NArY) involving the above groups X were synthesized, and their νmax values were recorded. Using these 12 νmax together with the 14 νmax values of Schiff bases taken from reference (total of 26 compounds), it was further verified that the σexcc(p) values are reliable by means of quantitative correlation method.
- Qu, Junyan,Cao, Chao-Tun,Cao, Chenzhong
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supporting information
(2018/04/24)
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- Water mediated Heck and Ullmann couplings by supported palladium nanoparticles: Importance of surface polarity of the carbon spheres
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Heterogeneous palladium nanoparticle catalysts that are supported on amphiphilic carbon spheres (Pd@CSP) have been utilized for water-mediated Heck coupling reactions of aryl halides with different alkenes under phosphine free as well as aerobic conditions. Furthermore, a variety of Heck coupling reactions using different bases and solvents, including organic polar and non-polar solvents, have been explored. Aryl bromides are also well activated in Heck coupling reactions in organic polar solvent and as well as in water. In addition, Ullmann coupling reactions of aryl iodides have been catalyzed in water with the aid of phase transfer catalysts (PTC) in moderate yields. A plausible mechanism for the catalytic activity of Pd@CSP in the case of the Ullmann reaction is also established. It has been demonstrated that the hydrophobic effects of the catalyst surface play an important role in catalyst activity in water. In addition, the E-factor analysis verified that our present protocol is significantly comparable with other catalytic systems and explains the improved greenness. Moreover, the catalyst described in this process is not only greener, but also retains its significant activity for up to four catalytic cycles for the Heck coupling reactions. The surface polarity of the amphiphilic carbon spheres results in higher activity under these conditions.
- Kamal, Ahmed,Srinivasulu, Vunnam,Seshadri,Markandeya, Nagula,Alarifi,Shankaraiah, Nagula
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p. 2513 - 2522
(2013/02/21)
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- Feeding the Heck reaction with alcohol: One-pot synthesis of stilbenes from aryl alcohols and bromides
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Aryl alcohols are employed as feedstock for the Heck reaction. Keggin-type heteropolyacids catalyse the selective dehydration of the alcohols to styrenes, which, in one-pot, undergo palladium-catalysed Heck arylation with aryl bromides, affording broadly functionalised stilbenes. The choice of solvent is critical for the cascade dehydration-Heck reaction, with electron-rich aryl alcohols preferring a basic medium while electron-deficient ones demanding solvents of lower basicity. Copyright
- Colbon, Paul,Barnard, Jonathan H.,Purdie, Mark,Mulholland, Keith,Kozhevnikov, Ivan,Xiao, Jianliang
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supporting information; scheme or table
p. 1395 - 1400
(2012/07/03)
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- Styrylheterocycles: A novel class of inhibitors on lipopolysaccharide-Induced nitric oxide production
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A series of styrylheterocycles was prepared and their inhibitory activities against nitric oxide (NO) production were evaluated in a cell culture system using lipopolysaccharide-stimulated RAW264.7 macrophage cells. Our studies have identified a new series of inhibitors on NO production, providing the basis for further development of potent inhibitors. The preliminary structure-activity relationship, to elucidate the essential structural requirements, has been described. Mechanistic studies suggest that the suppression of iNOS mRNA transcription is, at least in part, related to the inhibitory activity of styrylheterocycles.
- Lee, Sang Kook,Min, Hye Young,Huh, Sun Kyung,Kim, Eun-Young,Lee, Eunjung,Song, Soyoung,Kim, Sanghee
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p. 3689 - 3692
(2007/10/03)
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