• Title/Summary/Keyword: Mannich-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).

Intramolecular Oxa-Mannich Reaction of 1,3-Dihydro-2-benzofuran-1-ol for Efficient Synthesis of 1-Aminophthalan Derivatives

  • Kim, Heebum;Kim, Sung-Gon
    • Journal of the Korean Chemical Society
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    • v.66 no.1
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    • pp.9-14
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    • 2022
  • An efficient method for the synthesis of 1-aminophthalans has been developed. The intramolecular oxa-Mannich reaction of 1,3-dihydro-2-benzofuran-1-ols with p-toluenesulfonylamine in the presence of Cs2CO3 as a base, without using any catalyst, provided the desired 1-aminophthalans in moderate to good yields.

Synthesis of Mannich Bases Using Substitued Aromatic Alcohols with Secondary Amines: Relative Reactivity and Regioselectivity Depending on Substrates (치환된 방향족 알코올과 이차아민을 사용한 Mannich염기의 합성:기질에 따른 상대적인 반응성과 위치선택성)

  • Chi, Ki Whan;Ahn, Yoon Soo;Park, Tae Ho;Ahn, Jeong Soo;Kim, Hyun Ah;Park, Joo Yeon
    • Journal of the Korean Chemical Society
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    • v.45 no.1
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    • pp.51-60
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    • 2001
  • One-pot Mannich reaction of substituted hydroxy aromatic compounds with secondary amines in an aprotic solvent has been studied. The results demonstrate that the relative reactivity and regioselectivity of the Mannich reaction depend on the steric hindrance of amines as well as the nucleophilicity of hydroxy aromatic rings.

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Carbon-based Solid Acid Catalyzed One-pot Mannich Reaction: A Facile Synthesis of β-Amino Carbonyl Compounds

  • Davoodnia, Abolghasem;Tavakoli-Nishaburi, Afsaneh;Niloofar, Tavakoli-Hoseini
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.635-638
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    • 2011
  • A simple and efficient method for the synthesis of $\beta$-amino carbonyl compounds by one-pot three-component Mannich reaction of acetophenone, aromatic aldehydes and aromatic amines using a carbon-based solid acid (CBSA), as an effective and reusable catalyst, is described. The present methodology offers several advantages such as simple procedure with an easy work-up, shorter reaction times, and high yields.

Polyaniline/SiO2 Catalyzed One-pot Mannich Reaction: An Efficient Synthesis of β-amino Carbonyl Compounds (Polyaniline/SiO2를 이용한 one-pot Mannich 반응: β-amino carbonyl 화합물의 효율적인 합성)

  • Yelwande, Ajeet A.;Arbad, Balasaheb R.;Lande, Machhindra K.
    • Journal of the Korean Chemical Society
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    • v.55 no.4
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    • pp.644-649
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    • 2011
  • Polyaniline/$SiO_2$ catalyzed one-pot mannich reaction of acetophenone, aromatic aldehydes and aromatic amines are carried out in ethanol to afford various ${\beta}$-amino ketones. The various wt% of polyaniline were supported on pure silica synthesized by using chemical oxidative method. The catalyst prepared has been characterized by means of thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FT-IR). Solvent stability of catalyst was tested using UV-Visible spectroscopy. This protocol has several advantages such as high yield, simple work up procedure, non-toxic, clean, easy recovery and reusability of the catalyst.