• 제목/요약/키워드: Allylation

검색결과 44건 처리시간 0.021초

Alkylation and Allylation of Lithium Arylborates Factors Affecting the Di/Mono Substitution Ratio$^\dag$

  • 이호성;송양섭;이동두
    • Bulletin of the Korean Chemical Society
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    • 제8권5호
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    • pp.424-425
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    • 1987

  • Alkylation and allylation of arylborates give mono(ipso) and/or di(ortho and ipso) substitution products. Those factors which promote polarization or ionization of alkylating agents favor di substitution. The ${\sigma}$-type(ipso) substitution reaction of arylborates involves direct interaction of the carbon-boron bonds rather than predissociation of arylborates into aryllithiums and boranes.

  • https://doi.org/10.5012/bkcs.1987.8.5.424 인용 PDF

Regulation of Stereoselectivity and Reactivity in the Inter- and Intramolecular Allylic Transfer Reactions

  • Yu, Chan-Mo;Youn, Jin-soup;Jung, Hee-Keum
    • Bulletin of the Korean Chemical Society
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    • 제27권4호
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    • pp.463-472
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    • 2006

  • The preparation of enatiomerically enriched homoallylic alcohols through asymmetric addition of chiral allylic transfer reagents and allylating reagents with chiral catalysts to the carbonyl functionalities represents an important chemical transformation. Excellent progress has been made over past decade in the development and application of catalytic asymmetric allylic transfer reactions. In this account, our efforts for the various intermolecular allylic transfer reactions such as allylation, propargylation, allenylation, and dienylation utilizing accelerating strategy and sequential allylic transfer reactions to achieve multiple stereoselection mainly using transition metal catalysts are described.

  • https://doi.org/10.5012/bkcs.2006.27.4.463 인용 PDF KSCI

Synthesis of ($\pm$)-Methyl-(1-aryl-4-pyridin-3-yl-but-3-enyl)-amines

  • Jang, Jin-Hee;Sin, Kwan-Seog;Park, Hae-Il
    • Archives of Pharmacal Research
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    • 제24권6호
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    • pp.503-507
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    • 2001

  • trans-Metanicotine, a subtype (${\alpha}_4{\beta}_2$)-selective ligand for neuronal nicotinic acetylcholine receptor, is under clinical phase for Alzheimer's disease. An efficient synthetic route for ($\pm$)-methyl-(1-aryl-4-pyridin-3-yl-but-3-enyl)-am ices, derivatives of tracts-metanicotine, was explored. Allylation reaction of aryl aldimines with allylmagnesium bromide in THF gave ($\pm$)-methyl-(1-aryl-but-3-enyl)-amines. Protection of the amines with the Boc group and following Heck reaction of the N-Boc amines with 3-bromopyridine gave ($\pm$)-methyl-(1-aryl-4-pyridin-3-yl-but-3-enyl)-carbamic acid tert-butyl esters. Deprotection of the N-Boc group in aqueous 1 N-HCI solution gave the titled amines in good yields. Thus, trans-metanicotine analogues modified at the ${\alpha}-position$ of the methylamino group with amyl groups were obtained in 5 steps.

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A Concise Synthetic Pathway for trans-Metanicotine Analogues

  • Park, Hae-Il;Jang, Jin-Hee;Sin, Kwan-Seog
    • Archives of Pharmacal Research
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    • 제23권3호
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    • pp.202-205
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    • 2000

  • A convenient pathway for synthesis of trans-metanicotine analogues was developed. trans-Metanicotine, a subtype(${\alpha}4{\beta}2$)-selective ligand for neuronal nicotinic acetylcholine receptor, is under clinical phase for Alzheimer's disease. Zn-mediated allylation of allyl bromide and acetaldehyde followed by Heck reaction with 3-bromopyridine gave 5-pyridin-3-yl-pent-4-en-3-ol (2). Tosylation of 5-pyridin-3-yl-pent-4-en-3-ol followed by substitution reaction with methylamine in sealed tube gave methyl-(1-methyl-4-pyridin-3-yl-but-3-enyl)-amine (4) in good yields. Thus, trans-metanicotine analogues modified at the $\alpha$-position of the methylamino group with various functional groups can be obtained in 4 steps.

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