• Title/Summary/Keyword: N-Acyliminium ion

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Synthesis of Tetracyclic Pyrido[2,3-b]azepine Derivatives as Analogues of Mirtazapine via N-Acyliminium Ion Cyclization

  • Lee, Jae-Yeol;Bang, Sung-Hun;Lee, Sook-Ja;Song, Yun-Seon;Jin, Chang-Bae;Park, Ho-Koon;Lee, Yong-Sup
    • Bulletin of the Korean Chemical Society
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    • v.23 no.11
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    • pp.1623-1628
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    • 2002
  • Tetracyclic pyrido[2,3-b]azepine derivatives 4a-d and 4f as analogues of mirtazapine were synthesized via N-acyliminium ion cyclization by using aromatic rings such as benzene and thiophene ring as a ${\pi}-nucleophile$, and evaluated for the binding affinity for ${\alpha}2-adrenoceptor$. Among tested compounds, 2,3,9,13b-tetrahydro-1H-benzo[f]pyrrolo[2,1-a]pyrido[2,3-c]azepine (4a) was the most potent (Ki = 0.26 ${\mu}M)$ but showed about 3-fold less binding affinity than mirtazapine (Ki = 0.08 ${\mu}M)$ for a2-adrenoceptor.

The Versatile Conversion of Acyclic Amides to a-Alkylated Amines

  • Suh, Young-Ger;Lee, Do-Sang;Shin, Dong-Yun;Jung, Jae-Kyung;Kim, Seok-Ho
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.350.2-350.2
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    • 2002
  • The reaction of N-acyliminium ion with a variety of nucleophiles is one of the powerful method to introduce various substituents at the a-carbon of an amine. Particularly this type of inter and intramolecular C-C bond formation can be effectively applied to the synthesis of the bioactive natural or unnatural compounds as well as many bioactive peptidomimetics. Accordingly. much attention has been devoted to the practical and efficient methods for the generation of acyliminium ion precursors though there are many important aspects in the reaction involving N-acyliminium ions. (omitted)

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Mannich-type Reactions of in Situ Generated N-Acyliminium Ions from α-Amido p-Tolylsulfones with Silyl Enolates

  • Lee, Sang-Hyeup;Kadam, Santosh T.
    • Bulletin of the Korean Chemical Society
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    • v.32 no.10
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    • pp.3738-3742
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    • 2011
  • Bismuth tribromide ($BiBr_3$) catalyzed Mannich-type reactions of N-acyliminium ions which generated in situ from N-benzyloxycarbonylamino p-tolylsulfones have been developed. In the presence of catalytic amount of $BiBr_3$, N-benzyloxycarbonylamino p-tolylsulfones prepared from aromatic and aliphatic aldehydes reacted with silyl enol ether and silyl enol ester under mild reaction conditions to afford N-Cbz-protected ${\beta}$-amino ketones and N-Cbz-protected ${\beta}$-amino esters in moderate to good yield, respectively.

Zinc Mediated Barbier Type Allylation of Cyclic Imides and Subsequent Coupling Reactions with Carbon Nucleophiles

  • Kang, Seok-Won;Heo, Eun-Young;Jun, Jong-Gab;Kim, Sung-Hoon
    • Bulletin of the Korean Chemical Society
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    • v.25 no.12
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    • pp.1924-1928
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    • 2004
  • Allylations of N-benzyl and N-methyl cyclic imides were accomplished successfully under mild Barbier type conditions using zinc metal, allyl bromide and catalytic amount of $PbBr_2$. Subsequent coupling reactions with some carbon nucleophiles afforded 1,2- and 1,4-addition products in moderate to high yields.

Synthesis of Calycotomine via Pictet-Spengler Type Reaction of N,O-Acetal TMS Ethers as N-Acyliminium Ion Equivalents

  • Yang, Jung-Eun;In, Jin-Kyung;Lee, Mi-Sung;Kwak, Jae-Hwan;Lee, Hee-Soon;Lee, Soo-Jae;Kang, Han-Young;Suh, Young-Ger;Jung, Jae-Kyung
    • Bulletin of the Korean Chemical Society
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    • v.28 no.8
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    • pp.1401-1404
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    • 2007
  • An efficient Pictet-Spengler type reaction of N,O-acetal TMS ethers for the practical synthesis of 1-substituted tetrahydroquinolines, medicinally important alkaloids, has been accomplished. To demonstrate the versatility of this novel procedure, the total synthesis of calycotomine, a representative 1-hydroxymethyl substituted tetrahydroisoquinoline, is also described.