• Title/Summary/Keyword: Phosphonates

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Reactions of Phosphites with Nitroalkene Derivatives: Syntheses of $\beta$-Keto Phosphonates and $\alpha$-Cyanoalkylphosphonates

  • 김대영;오동영
    • Bulletin of the Korean Chemical Society
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    • v.18 no.9
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    • pp.994-998
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    • 1997
  • The addition of phosphite derivatives 1 to nitroalkenes 2 afforded α-phosphoryl nitronates which, on treatment MCPBA, were converted β-keto phosphonates 3. A versatile reaction conditions to generate α-phosphoryl nitronates were examined. α-Cyanoalkylphosphonates 6 were prepared from the diethyl trimethylsilyl phosphite (DTSP) 1c with nitroalkenes 2 and followed by reduction.

The Synthesis of Diverse Adenosine 5'-phosphonate Analogues as Chain Terminators against Hepatitis C Virus (HCV)

  • Kim, Bo-Seung;Kim, Beom-Tae;Hwang, Ki-Jun
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1643-1648
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    • 2010
  • Adenosine 5'-phosphonates have been reported as potential chain terminators against Hepatitis C virus (HCV); therefore, we developed convenient sequences for synthesis of modified adenosine 5'-phosphonates in which the hydroxyl group at 2' or 3'-position of the sugar moiety is substituted with the azido or amino group and the oxymethyl group at the 4'-position is modified by the ethylene or vinyl group. This synthetic sequence can provide six adenosine 5'-phosphonates via one protocol, and is considered to be very efficient and a convenient route of synthesis. An assay of adenosine 5'-phosphonate analogues (1, 2, 3, 4, 5, and 6) against HCV infection is now in progress.

Sulphamic Acid: an Efficient Catalyst for the Synthesis of α-HydroxyPhosphonates Using Ultrasound Irradiation (술팜산: 초음파 조사를 이용한 α-히드록시 인산염 합성의 효과적인 촉매)

  • Sadaphal, Sandip A.;Sonar, Swapnil S.;Pokalwar, Rajkumar U.;Shitole, Nanasaheb V.;Shingare, Murlidhar S.
    • Journal of the Korean Chemical Society
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    • v.53 no.5
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    • pp.536-541
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    • 2009
  • Sulphamic acid has been exploited as a cost-effective catalyst and green alternative for conventional acidic materials to synthesize $\alpha$-hydroxy phosphonates under solvent-free condition. The reaction carried out using ultrasound irradiation with better yields and shorter reaction time.

Enantioselective Fluorination of β-Keto Phosphonates and β-Ketoesters Catalyzed by Chiral Palladium Complexes

  • Lee, Na-Ri;Kim, Sun-Mi;Kim, Dae-Young
    • Bulletin of the Korean Chemical Society
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    • v.30 no.4
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    • pp.829-836
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    • 2009
  • The catalytic enantioselective electrophilic fluorinations of active methine compounds promoted chiral palladium complexes have been developed. Treatment of $\beta$-keto phosphonates and $\beta$-ketoesters with N-fluorobenzenesulfonimide as the fluorine source under mild reaction conditions afforded the corresponding $\alpha$-fluorinated adducts in high yields with excellent enantiomeric excesses (up to 99% ee). These reactions can be conducted in alcoholic solvents without any precaution to exclude water and moisture.

Formation and Reactions of α-Phosphoryl Thiocarbocations: Synthesis of α-Sulfenyl Phosphonates

  • 김택현;오동영
    • Bulletin of the Korean Chemical Society
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    • v.16 no.7
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    • pp.609-613
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    • 1995
  • The reaction of chloro(methylthio and arylthio)methanephosphonate (1) and Pummerer-type reaction of sulfinylmethanephosphonate (2) with nucleophiles such as aromatic compounds and thiols were examined. The direct chlorination of (methylthio and arylthio)methanephosphonate with N-chlorosuccinimide (NCS) led to the formation of monochlorinated phosphonates (1) in good yield. The reaction of 1 with aromatic compounds and thiols in the presence of stannic chloride afforded a variety of aryl(methylthio)methanephosphonates (3) and thioacetals of formylphosphonates (4), respectively. Phosphonates 3 and 4 were also obtained from the reaction of Pummerer intermediate, generated from sulfinylmethanephosphonate (2), with aromatic compounds and thiols, respectively. A versatile reaction conditions to generate Pummerer intermediate were examined. The best condition was the combination of trifluoroacetic anhydride with stannic chloride. All reactions may involve an initial formation of α-phosphoryl thiocarbocation and a subsequent nucleophilic attack of aromatic compounds and thiols.

Neat Synthesis and Anti-oxidant Activity of α-Hydroxyphosphonates

  • Rao, K. Uma Maheswara;Sundar, Ch. Syama;Prasad, S. Siva;Rani, C. Radha;Reddy, C. Suresh
    • Bulletin of the Korean Chemical Society
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    • v.32 no.9
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    • pp.3343-3347
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    • 2011
  • A simple efficient and neat synthesis of ${\alpha}$-hydroxy phosphonates has been accomplished from aromatic/heterocyclic aldehydes and diethyl phosphite using $KHSO_4$ as a catalyst under solvent-free conditions at ambient temperature. These compounds are characterized by spectral and analytical data and tested for their anti-oxidant activity.