- Organophotochemical SNAr Reactions of Mildly Electron-Poor Fluoroarenes
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C–F functionalization of arenes with a range of alcohol and pyrazole nucleophiles has been achieved without the need for metal catalysts or highly electron-poor substrates. Treatment of fluoroarenes with alcohols or pyrazoles and DDQ under irradiation by blue LED light provides the corresponding substituted products. The procedure is complementary to classical SNAr chemistry which generally requires basic reaction conditions and high temperatures, and provides products under non-basic conditions at ≈ 40 °C.
- Burton, Jonathan W.,Genovino, Julien,Lian, Yajing,Monck, Nat,Sheridan, Thomas,Yayla, Hatice G.
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supporting information
p. 2766 - 2770
(2020/05/18)
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- BORON-CONTAINING SMALL MOLECULES
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This invention provides novel compounds, methods of using the compounds, and pharmaceutical formulations comprising the compounds.
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Paragraph 0296; 0297
(2013/06/04)
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- A simple, efficient and regioselective oxychlorination of aromatic compounds using ammonium chloride and oxone
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A simple, efficient, mild and regioselective method for oxychlorination of aromatic compounds is reported. The electrophilic substitution of chlorine generated in situ from NH4Cl as a chlorine source and oxone as an oxidant is reported for the first time.
- Narender,Mohan, K.V.V. Krishna,Srinivasu,Kulkarni,Raghavan
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p. 1335 - 1338
(2007/10/03)
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- Diflunisal Analogues Stabilize the Native State of Transthyretin. Potent Inhibition of Amyloidogenesis
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Analogues of diflunisal, an FDA-approved nonsteroidal antiinflammatory drug (NSAID), were synthesized and evaluated as inhibitors of transthyretin (TTR) aggregation, including amyloid fibril formation. High inhibitory activity was observed for 26 of the compounds. Of those, eight exhibited excellent binding selectivity for TTR in human plasma (binding stoichiometry > 0.50, with a theoretical maximum of 2.0 inhibitors bound per TTR tetramer). Biophysical studies reveal that these eight inhibitors dramatically slow tetramer dissociation (the rate-determining step of amyloidogenesis) over a duration of 168 h. This appears to be achieved through ground-state stabilization, which raises the kinetic barrier for tetramer dissociation. Kinetic stabilization of WT TTR by these eight inhibitors is further substantiated by the decreasing rate of amyloid fibril formation as a function of increasing inhibitor concentration (pH 4.4). X-ray cocrystal structures of the TTR·182 and TTR·202 complexes reveal that 18 and 20 bind in opposite orientations in the TTR binding site. Moving the fluorines from the meta positions in 18 to the ortho positions in 20 reverses the binding orientation, allowing the hydrophilic aromatic ring of 20 to orient in the outer binding pocket where the carboxylate engages in favorable electrostatic interactions with the ε-ammonium groups of Lys 15 and 15′. The hydrophilic aryl ring of 18 occupies the inner binding pocket, with the carboxylate positioned to hydrogen bond to the serine 117 and 117′ residues. Diflunisal itself appears to occupy both orientations based on the electron density in the TTR·12 structure. Structure-activity relationships reveal that para-carboxylate substitution on the hydrophilic ring and dihalogen substitution on the hydrophobic ring afford the most active TTR amyloid inhibitors.
- Adamski-Werner, Sara L.,Palaninathan, Satheesh K.,Sacchettini, James C.,Kelly, Jeffery W.
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p. 355 - 374
(2007/10/03)
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- Synthesis of hydroxylated PCB metabolites with the Suzuki-coupling
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An improved synthesis of hydroxylated polychlorinated biphenyls (PCBs) which are structurally related to the major hydroxy PCB congeners identified in human plasma is described. The coupling of (chlorinated) aryl boronic acids with bromochloro anisoles using the standard conditions of the Suzuki coupling gave the desired hydroxylated PCB metabolites in good to excellent yields. The approach offers the advantage of high selectivity and good yields compared to conventional methods such as the Cadogan reaction and allows the use of less toxic starting materials.
- Lehmler, Hans-Joachim,Robertson, Larry W.
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p. 1119 - 1127
(2007/10/03)
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- Novel terphenyls as selective cyclooxygenase-2 inhibitors and orally active anti-inflammatory agents
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A novel series of terphenyl methyl sulfones and sulfonamides have been shown to be highly potent and selective cyclooxygenase-2 (COX-2) inhibitors. The sulfonamide analogs 17 and 21 were found to be much more potent COX-2 inhibitors and orally active anti-inflammatory agents than the corresponding methyl sulfone analogs 16 and 20, respectively, albeit with some decrease in COX-2 selectivity. Structure-activity relationship studies have determined that incorporation of two fluorine atoms in the central phenyl group, as in 20 and 21, is extremely advantageous for both in vitro COX-2 potency and selectivity as well as in vivo activity. Several noticeable examples in the 1,2-diaryl-4,5-difluorobenzenesulfonamide series are 21a-c,k,l,n (COX-2, IC50 = 0.002-0.004 μM), in which all have in vitro COX-1/COX-2 selectivity > 1000. In addition, sulfonamides 21a,b,d,g,j,m,n,q were shown to have greatly enhanced oral activity with more than 90% inhibition of prostaglandin E2 production in the air pouch model of inflammation. Furthermore, sulfonamide 21b was found to be very active in the rat adjuvant-induced arthritis model (ED50 = 0.05 mg/kg) and carrageenan-induced hyperalgesia assay (ED50 = 38.7 mg/kg) with no indication of gastrointestinal toxicity in rats at doses as high as 200 mg/kg.
- Li, James J.,Norton, Monica B.,Reinhard, Emily J.,Anderson, Gary D.,Gregory, Susan A.,Isakson, Peter C.,Koboldt, Carol M.,Masferrer, Jaime L.,Perkins, William E.,Seibert, Karen,Zhang, Yan,Zweifel, Ben S.,Reitz, David B.
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p. 1846 - 1856
(2007/10/03)
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- Formation of Nonaromatic Products in the Chlorination of Simple Substituted Aromatic Ethers
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The neat chlorination of 4-chloroanisole produces 1,3,4,5,6-pentachloro-4-methoxycyclohexene in 35percent yield.Mono- and dichlorinated anisoles and a variety of simple substituted anisoles were chlorinated to determine the generality of nonaromatic product formation. 3,4-Dichloroanisole, 4-fluoroanisole, 4-bromoanisole, 4-methylanisole, and 4-chlorophenetole form similar products based on their spectral properties.These products are proposed to form by a cis-1,2-chlorine addition followed by rapid cis-1,4 chlorine addition.On the basis of the NMR data, a predominate configuration is proposed.
- Watson, William David
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p. 5270 - 5276
(2007/10/02)
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