• Title/Summary/Keyword: Mannich-type reaction

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Organocatalytic Mannich-Type Reactions of Cyclic N-Sulfimines with Trimethylsiloxyfuran and Pyrazolin-5-one

  • Lee, Jiseon;Kim, Sung-Gon
    • Journal of the Korean Chemical Society
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    • v.63 no.5
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    • pp.346-351
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    • 2019
  • Mannich-type reactions of cyclic N-sulfimines with 2-trimethylsiloxyfuran and pyrazolin-5-one have been developed using phosphoric acid (PA) as an organocatalyst. 2-Trimethylsiloxyfuran underwent a vinylogous Mannich-type reaction with cyclic N-sulfimines in the presence of the PA catalyst to give sulfamidate ${\gamma}$-butenolides in good yields and with high diastereoselectivities (up to 90% yield and 7:1 dr). In addition, the reaction between pyrazolin-5-one and a diverse range of cyclic N-sulfimines provided access to sulfamidates in good to high yields (up to 94% yield).

Asymmetric Mannich-type Reactions of Fluorinated Ketoesters with Binaphthyl-Modified Thiourea Catalysts

  • Kang, Young-Ku;Yoon, Sung-Je;Kim, Dae-Young
    • Bulletin of the Korean Chemical Society
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    • v.32 no.4
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    • pp.1195-1200
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    • 2011
  • The catalytic enantioselective Mannich-type reaction promoted by chiral binaphthyl-modified bifunctional organocatalysts is described. The treatment of ${\alpha}$-fluoro-${\beta}$-ketoesters with N-Boc imines under mild reaction conditions afforded the corresponding ${\beta}$-aminated ${\alpha}$-fluoro-${\beta}$-ketoesters with excellent enantioselectivities (up to 98% ee).

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.

Applications of Cross-linked Poly(4-vinylpyridine/styrene) Copolymer supported Ytterbium(III) Triflate in Mannich-type Reaction:Three Component One-pot Synthesis of β-Aminoketones

  • Lee, Sang-Hyeup;Lee, Byoung-Se
    • Bulletin of the Korean Chemical Society
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    • v.30 no.3
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    • pp.551-555
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    • 2009
  • The ytterbium catalyst immobilized on the cross-linked poly(4-vinylpyridine/styrene) copolymer (P/S-Yb) was applied in the Mannich-type, three component one-pot synthesis of $\beta$-aminoketones. This catalytic system showed excellent catalytic activity and selectivity which resulted in the exclusive formation of $\beta$-aminoketone. The applicability of this immobilized catalyst system was shown by the reusability test and again highlighted by the synthesis of a $\beta$-aminoketone library using a broad range of substrates.

Oxazole, Pyrazole and Piperidine Derivatives Having an o-Hydroxy-aryl Moirty with Anticipated Molluscicidal Activity

  • Nawwar, Galal-A.M.;Swellem, Randa-H.;Ibrahim, Amal-M
    • Archives of Pharmacal Research
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    • v.17 no.2
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    • pp.66-70
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    • 1994
  • The condensation reactions of hippuric acid and tis furyl derivative with salicyladehydes or that of salicylhippuric acid analogues with furadehyde led to the comesponding oxazoles. These wre subsequently treated with hydrazine hydrate, hydroxylamine or subjected to alkaline hydrolysis to yield new o-hydroxyaryl or salicyl containing derivatives. 5-Substituted salicylanilides were treated with piperidine and formaldehyde in a Mannich type reaction affording the corresponding 3-(N-piperidinomethyl) salicylanilides. It was noticed that the presence of an electron donating group in in position 3 in the salicylanilide moiety decrease the mollusicidal activity.

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An Efficient Synthesis of 3,4-Dihydro-3-substituted-2H-naphtho[2,1-e][1,3]oxazine Derivatives Catalyzed by Zirconyl(IV) Chloride and Evaluation of its Biological Activities

  • Kategaonkar, Amol H.;Sonar, Swapnil S.;Pokalwar, Rajkumar U.;Kategaonkar, Atul H.;Shingate, Bapurao B.;Shingare, Murlidhar S.
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1657-1660
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    • 2010
  • An efficient and novel one-pot synthesis of new 3,4-dihydro-3-substituted-2H-naphtho[2,1-e][1,3]oxazine derivatives from 1-naphthol, various anilines and formalin at room temperature grinding is presented. The six-membered N,O-heterocyclic skeleton was constructed via zirconyl(IV) chloride promoted Mannich type reaction. In vitro antimicrobial activities of synthesized compounds have been investigated against Gram-positive Bacillus subtilis, Gram negative Escherichia coli and two fungi Candida albicans and Aspergillus niger in comparison with standard drugs. The results of preliminary bioassay indicate that some of title compounds possess significant antibacterial and antifungal activity.