• 제목/요약/키워드: Allylation

검색결과 44건 처리시간 0.016초

Pd-Catalyzed Substitution Reactions with Organoindium Reagents in situ Generated from Indium and Allyl or Propargyl Halides

  • Lee, Phil-Ho;Shim, Eun-Kyong;Lee, Koo-Yeon;SeoMoon, Dong;Kim, Sun-Dae
    • Bulletin of the Korean Chemical Society
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    • 제26권1호
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    • pp.157-160
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    • 2005
  • Allylindium and propargylindium reagents in situ generated from the reactions of indium with allyl halides and propargyl halides could participate as nucleophiles in Pd-catalyzed substitution reactions of allyl carbonates to produce 1,5-dienes and 1,5-enynes in good yields. $\beta$-Hydride elimination products were produced in case of carbonates having $\beta$-hydrogens. Because organoindium reagents obtained from allyl or propargyl halides and indium have previously not been used to Pd-catalyzed allylic and propargylic substitution reactions, these results should provide more opportunities for the development of new C-C bond forming reactions.

A Convenient Allylation of 1,n-Dicarbonyl Compounds Using Organoindium Reagents

  • 이필호;동서문;이구연
    • Bulletin of the Korean Chemical Society
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    • 제22권12호
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    • pp.1380-1384
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    • 2001
  • The chemoselective reactions of 1,n-dicarbonyl compounds with allyl halides using indium metal were investigated. $\alpha-Ketoesters$ such as ethyl pyruvate, ethyl 3-methyl-2-oxobutyrate and ethyl benzoylformate reacted with a variety of allyl halides i n the presence of indium to afford hydroxy unsaturated carbonyl compounds in good to excellent yields in MeOH/HCl at $25^{\circ}C.$ For the allyl bromide, the presence of various substituents at the $\alpha$ or $\gamma$ position exhibited little effects on both the reaction rates and yields. Ethyl acetoacetate or ethyl levulinate was treated with allylindium reagent to give hydroxy unsaturated carbonyl compounds in good yield. These results mean that both reactivity and selectivity are independent of the distance between carbonyl groups. 2,3-Butanedione or 1-phenyl-1,2-propanedione reacted with allylindium to produce monoallylation product as major compound.

Synthesis of α-Ketobutyrolactones and γ-Hydroxy-α-Keto Acids

  • Kang, Han-Young;Ji, Yu-Mi;Yu, Yeon-Kwon;Yu, Ji-Yeon;Lee, Young-Hoon;Lee, Sang-Joon
    • Bulletin of the Korean Chemical Society
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    • 제24권12호
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    • pp.1819-1826
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    • 2003
  • In connection with the studies for developing new enzymes that could be useful in organic synthesis, practical preparation of racemic and enantiopure forms of ${\gamma}$-hydroxy-${\alpha}$-keto acids has been successfully achieved. For racemic form of ${\gamma}$-hydroxy-${\alpha}$-keto acids, indium-mediated allylation of aldehydes with 2-(bromomethyl)acrylic acid has been employed as a key step. Oxidative cleavage of the thus formed 2-methylenebutyrolactones provided the desired ${\alpha}$-ketobutyrolactones. Enzymatic resolution of the ${\gamma}$-hydroxy-${\alpha}$-methylene esters provided the desired${\gamma}$-hydroxy-${\alpha}$-methylene acids which were successfully converted to ${\gamma}$-hydroxy-${\alpha}$-ketobutyrolactones in optically pure forms.