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Quaternary Ammonium Salts in Organocatalysis New Book

  • Asymmetric Organocatalysis

    Asymmetric Organocatalysis
    Albrecht Berkessel, Harald Gröger

    Although replacement of the required mercury salt would be desirable, this in situ preparation of the enolate and … Aldol reactions using a quaternary chinchona alkaloid-based ammonium salt as organocatalyst Several quaternary ammonium  …

  • Comprehensive Enantioselective Organocatalysis

    Comprehensive Enantioselective Organocatalysis
    Peter I. Dalko

    Indeed, phasetransfercatalysis hasinmany instances been applied successfully with quaternary ammonium salts derived from natural cinchona alkaloids [112]. The first exampleof phasetransfer catalysis witha cinchonaalkaloid derivative was  …

  • Stereoselective Organocatalysis

    Stereoselective Organocatalysis
    Ramon Rios Torres

    N\ ' so 0 BzN' \ H (a) (b) 2.3.3 Phase-Transfer and Asymmetric Countercation- Directed Catalysis After the first successful application of Cinchona alkaloid- based quaternary amonium salts as chiral phase-transfer catalysts in 1984 [187], the use …

  • Enantioselective Organocatalysis

    Enantioselective Organocatalysis
    Peter I. Dalko

    Takashi Ooi and Keiji Maruoka 4.1 Introduction Chiral, nonracemic quaternary ammonium salts have been emerging as a powerful metal-free catalyst for effecting various stereoselective bond-forming reactions under mild conditions.

  • Organocatalysis

    Organocatalysis
    Manfred Reetz, Benjamin List, Stefan Jaroch, Hilmar Weinmann

    A quaternary ammonium salt was easily synthesized on a modified MeOPEG, and this supported catalyst was shown to be an efficient and recoverable promoter of several reactions carried out under PTC conditions. Catalyst 13 showed a …

  • Organocatalytic Enantioselective Conjugate Addition Reactions

    Organocatalytic Enantioselective Conjugate Addition Reactions
    Jose L. Vicario

    N R R Quaternary ammonium cation for interacting with the nucleophile anion Stabilizes developing negative charge … of the catalyst Figure 5.3 Relevant aspects of the design of axially chiral ammonium salts as PTC catalysts. the C-9 oxygen …

  • Asymmetric Organocatalysis in Natural Product Syntheses

    Asymmetric Organocatalysis in Natural Product Syntheses
    Mario Waser

    JAm Chem Soc 111: 2353 Corey EJ, Xu F, Noe MC (1997) A Rational Approach to Catalytic Enantioselective Enolate Alkylation Using a Structurally Rigidified and Defined Chiral Quaternary Ammonium Salt Under Phase Transfer Conditions.

  • Polymeric Chiral Catalyst Design and Chiral Polymer Synthesis

    Polymeric Chiral Catalyst Design and Chiral Polymer Synthesis
    Shinichi Itsuno

    The facile immobilization allowed for combinatorial screening of the desired chiral organocatalysts for the asymmetric … One of the best immobilization methods for these chiral organocatalysts with quaternary ammonium salt at present is …

  • Recent Developments in Asymmetric Organocatalysis

    Recent Developments in Asymmetric Organocatalysis
    Hélène Pellissier

    However, examples of organocatalytic synthesis of these products are especially scarce, probably due to their ease of undesired … In 2008, Itsuno et al. developed a novel immobilisation method of quaternary ammonium salts through an ionic …

  • Sustainable Catalysis

    Sustainable Catalysis
    Michael North

    Amines. and. Their. Salts. as. Asymmetric. Organocatalysts. TAICHI KANO* AND KEIJI MARUOKA* Department of … number of chiral amines and quaternary ammonium salts have been developed and widely employed as organocatalysts in …

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