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Asymmetric Mannich-Type Reaction (asymmetric + mannich-type_reaction)

Distribution by Scientific Domains
Chemistry100%
Distribution within Chemistry
Organic Chemistry80%
General & Introductory Chemistry20%

Kinds of Asymmetric Mannich-Type Reaction

  • catalytic asymmetric mannich-type reaction
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    Selected Abstracts

    Asymmetric Mannich-Type Reaction of a Chiral N -(tert -Butylsulfinyl) Ketimine with Imines: Application to the Synthesis of Chiral 1,3-Diamines

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2006
    Cui-Hua Zhao
    Abstract Deprotonation of the chiral N -(tert -butylsulfinyl) ketimine 1 followed by trapping with imines 2 afforded the ,-aminoimines 3 as the Mannich-type products in high diastereoselectivities (99:1 dr). As versatile synthons chiral ,-amino imines 3 could be transformed into enantiomeric ,-amino ketone and chiral syn - or anti -1,3-diamines with high diastereomeric excess by hydrolysis or reduction, respectively. Moreover, the nucleophilic addition of organometallicreagents to chiral ,-amino imines 3 could provide 1,1,3-trisubstituted 1,3-diamines with high diastereoselectivities. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]

    ChemInform Abstract: Chiral Ammonium Betaines: A Bifunctional Organic Base Catalyst for Asymmetric Mannich-Type Reaction of ,-Nitrocarboxylates.

    CHEMINFORM, Issue 1 2009
    Daisuke Uraguchi
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: Direct Catalytic Asymmetric Mannich-Type Reaction of ,-Keto Phosphonate Using a Dinuclear Ni2,Schiff Base Complex.

    CHEMINFORM, Issue 47 2008
    Zhihua Chen
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    A Direct Catalytic Asymmetric Mannich-Type Reaction via a Dinuclear Zinc Catalyst: Synthesis of Either anti- or syn-,-Hydroxy-,-amino Ketones.

    CHEMINFORM, Issue 28 2006
    Barry M. Trost
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    Direct Catalytic Asymmetric Mannich-Type Reaction of Hydroxyketone Using a Et2Zn/Linked-BINOL Complex: Synthesis of Either anti- or syn-,-Amino Alcohols.

    CHEMINFORM, Issue 46 2004
    Shigeki Matsunaga
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Catalytic Asymmetric Mannich-Type Reactions Activated by ZnF2 Chiral Diamine in Aqueous Media.

    CHEMINFORM, Issue 16 2006
    Tomoaki Hamada
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    Direct Organocatalytic Asymmetric Mannich-Type Reactions in Aqueous Media: One-Pot Mannich-Allylation Reactions.

    CHEMINFORM, Issue 21 2003
    Armando Cordova
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Phase-Transfer-Catalyzed Enantioselective Mannich Reaction of Malonates with ,-Amido Sulfones

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 15 2006
    Francesco Fini
    Abstract The highly enantioselective reaction between in situ generated, Cbz-protected azomethines and malonates in the presence of 150 mol,% of potassium carbonate (50,% w/w) and 1 mol,% of quinine-derived quaternary ammonium bromides as phase-transfer organocatalysts has been developed. This study reports a novel approach for the asymmetric Mannich-type reaction and a wide range of azomethines, including those derived from enolizable aldehydes, is tolerated by the present system. The adducts, obtained in excellent yields with ee up to 98,%, are suitable precursors of optically pure ,-amino acids. [source]

    Organocatalytic Asymmetric Mannich Reactions with N -Boc and N -Cbz Protected ,-Amido Sulfones (Boc: tert -Butoxycarbonyl, Cbz: Benzyloxycarbonyl)

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 29 2007
    Olindo Marianacci
    Abstract Different malonates and ,-ketoesters can react with N - tert -butoxycarbonyl- (N -Boc) and N -benzyloxycarbonyl- (N -Cbz) protected ,-amido sulfones in an organocatalytic asymmetric Mannich-type reaction. The reaction makes use of a simple and easily obtained phase-transfer catalyst and proceeds under very mild and user-friendly conditions. The optimised protocol avoids the preparation and the isolation of the relatively unstable N -Boc and N- Cbz imines that are generated in situ from the bench-stable ,-amido sulfones. The corresponding Mannich bases are generally obtained in good yields and enantioselectivities, and can be readily transformed into key compounds, such as optically active ,3 -amino acids in one easy step. Enantioenriched N -Boc and N -Cbz protected ,-amino acids that are suitable for peptide synthesis are also available from the Mannich adducts through simple manipulations. Control experiments showed the dual role of the enolate,catalyst ion pair in this reaction, as well as the crucial role of the presence of water to achieve high enantioselectivities. [source]

    PdII -Catalyzed Asymmetric Addition Reactions of 1,3-Dicarbonyl Compounds: Mannich-Type Reactions with N -Boc Imines and Three-Component Aminomethylation

    CHEMISTRY - AN ASIAN JOURNAL, Issue 8-9 2008
    Yoshitaka Hamashima Dr.
    Abstract This paper describes catalytic asymmetric Mannich-type reactions of ,-ketoesters and malonates using chiral palladium complexes. Although readily enolizable, carbonyl compounds are attractive substrates, the use of such compounds as nucleophiles in Mannich-type reactions has not been extensively investigated. In the presence of chiral Pd aqua complexes (2.5,mol,%), ,-ketoesters reacted with various N -Boc imines (Boc=tert -butoxycarbonyl) to afford the desired ,-aminocarbonyl compounds in good yield with high to excellent stereoselectivity (up to 96:4 d.r., 95,99,%,ee in most cases). In these reactions, construction of highly crowded vicinal quaternary and tertiary carbon centers was achieved in one step. A chiral Pd enolate is considered to be the key intermediate. To elucidate the stereoselectivity observed in the reaction, possible transition-state models are discussed, taking into account steric and stereoelectronic effects. Furthermore, this catalytic system was applied to the Mannich-type reaction of malonates with N -Boc imine as well as one-pot classical aminomethylation of ,-ketoesters using benzylamine salt and formalin. The reactions proceeded smoothly, and the corresponding Mannich products were obtained in high yield with moderate to good enantioselectivity. [source]