- RADICAL CYCLIZATION OF α-FLUORO-α-IODO AND α-IODO ESTERS AND AMIDES
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The free radical cyclization of various unsaturated α-fluoro-α-iodo and α-iodo esters and amides is described.Unusual 12-membered dilactones and 18-membered trilactones were obtained under the standard atom transfer cyclization reaction conditions.
- Barth, Francis,O-Yang, Counde
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- FUSED BICYCLIC HETEROCYCLES AS THEREAPEUTIC AGENTS
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This disclosure relates to compounds, pharmaceutical compositions comprising them, and methods of using the compounds and compositions for treating diseases related to nicotinamide phosphoribosyltransferase (NAM FT) expression. More particularly, this disclosure relates to fused bicyclic heterocyclic compounds and pharmaceutical compositions thereof, methods of inhibiting NAM FT with these compounds, and methods of treating diseases related to NAMPT expression.
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Paragraph 0255
(2020/05/15)
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- Asymmetric synthesis of chiral organofluorine compounds: Use of nonracemic fluoroiodoacetic acid as a practical electrophile and its application to the synthesis of monofluoro hydroxyethylene dipeptide isosteres within a novel series of HIV protease inhibitors
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Two stereoselective routes to a series of diastereomeric inhibitors of HIV protease, monofluorinated analogues of the Merck HIV protease inhibitor indinavir, are described. The two routes feature stereoselective construction of the fluorinated core subunits by asymmetric alkylation reactions. The first-generation syntheses were based on the conjugate addition of the lithium enolate derived-from pseudoephedrine α-fluoroacetamide to nitroalkene 12, a modestly diastereoselective transformation. A more practical second-generation synthetic route was developed that is based on a novel method for the asymmetric synthesis of organofluorine compounds, by enolate alkylation using optically active fluoroiodoacetic acid as the electrophile in combination with a chiral amide enolate. Resolution of fluoroiodoacetic acid with ephedrine provides either enantiomeric form of the electrophile in ≥96% ee. Alkylation reactions with this stable and storable chiral fluorinated precursor are shown to proceed in a highly stereospecific manner. With the development of substrate-controlled syn- or anti-selective reductions of α-fluoro ketones 44 and 45 (diastereomeric ratios 12:1-84:1), efficient and stereoselective routes to each of the four targeted inhibitors were achieved. The optimized synthetic route to the most potent inhibitor (syn,syn-4, Ki = 2.0 nM) proceeded in seven steps (87% average yield per step) from aminoindanol hydrocinnamide 40 and (S)-fluoroiodoacetic acid, and allowed for the preparation of more than 1 g of this compound. The inhibition of HIV-1 protease by each of the fluorinated inhibitors was evaluated in vitro, and the variation of potency as a function of inhibitor stereochemistry is discussed.
- Myers,Barbay,Zhong
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p. 7207 - 7219
(2007/10/03)
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- Novel and practical preparation of α-fluoro-functionalized esters from fluoroiodoacetates
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The addition reaction of fluoroiodoacetates 2 to various electron-rich alkenes 3 initiated by iron powder in dry THF at 70-80°C gave 1:1 adducts 4 in good yields. A variety of functionalities in the alkenes such as trimethylsilyl, alkoxy, acetoxy, hydroxy and ester could be tolerated under the reaction conditions. Reduction of the adducts 4 with Zn-AcOH in ethanol or Zn-NiCl2·OH2O in moist THF was readily accomplished, and the overall procedure was amenable to a convenient one-flask procedure. Treatment of fluoroiodoacetates 2 with electron-deficient alkenes 7 in the presence of an Fe-CrCl3·OH2O-bpy bimetal redox system in ethanol at 70-80°C resulted in the formation of iodine-free 1:1 adducts 8 in moderate to good yields. It is proposed that the addition reactions of fluoroiodoacetates 2 to electronrich and electron-deficient alkenes proceeded through a single-electron-transfer mechanism.
- Zhi, Chengxin,Chen, Qing-Yun
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p. 1741 - 1747
(2007/10/03)
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- The Stereoselective Construction of (Z)-3-Aryl-2-fluoroalkenoates
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The use of 2,4,6-trimethylphenyl α-silyl-α-fluoroacetate in the Peterson olefination reaction leads to the highly stereoselective formation of (Z)-3-aryl-2-fluoroalkenoates via an aldol reaction most likely proceeding through an open transition state sinc
- Welch, John T.,Herbert, Randal W.
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p. 4782 - 4784
(2007/10/02)
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