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    Knoevenagel Condensation CLLG

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    priyanshu chauhan
    Knoevenagel condensation is a reaction that forms an α,β-unsaturated carbonyl compound (enone) from an activated methylene compound and an aldehyde or ketone using an amine base catalyst. It involves deprotonation of the methylene compound, followed by nucleophilic addition to the carbonyl group and dehydration. The reaction is widely used to form C=C bonds and is an important step in synthesizing natural products, drugs, polymers, and agrochemicals like lumefantrine and coumarin.

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    Knoevenagel Condensation CLLG

    Uploaded by

    priyanshu chauhan
    66 views8 pages
    Knoevenagel condensation is a reaction that forms an α,β-unsaturated carbonyl compound (enone) from an activated methylene compound and an aldehyde or ketone using an amine base catalyst. It involves deprotonation of the methylene compound, followed by nucleophilic addition to the carbonyl group and dehydration. The reaction is widely used to form C=C bonds and is an important step in synthesizing natural products, drugs, polymers, and agrochemicals like lumefantrine and coumarin.

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    knoevenagel condensation cllg (1)

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    Knoevenagel condensation is a reaction that forms an α,β-unsaturated carbonyl compound (enone) from an activated methylene compound and an aldehyde or ketone using an amine base catalyst. It involves deprotonation of the methylene compound, followed by nucleophilic addition to the carbonyl group and dehydration. The reaction is widely used to form C=C bonds and is an important step in synthesizing natural products, drugs, polymers, and agrochemicals like lumefantrine and coumarin.

    Copyright:

    © All Rights Reserved
    Download as PPT, PDF, TXT or read online from Scribd
    Download as ppt, pdf, or txt
    66 views8 pages

    Knoevenagel Condensation CLLG

    Uploaded by

    priyanshu chauhan
    Knoevenagel condensation is a reaction that forms an α,β-unsaturated carbonyl compound (enone) from an activated methylene compound and an aldehyde or ketone using an amine base catalyst. It involves deprotonation of the methylene compound, followed by nucleophilic addition to the carbonyl group and dehydration. The reaction is widely used to form C=C bonds and is an important step in synthesizing natural products, drugs, polymers, and agrochemicals like lumefantrine and coumarin.

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    © All Rights Reserved
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    Download as ppt, pdf, or txt
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    Knoevenagel condensation

    By DEEPTI MANDELIYA
    S.G.S.I.T.S., Indore
    Tabel of content

     Definnation: what is knoevenagel condensation?


     Example of knoevenagel condesation.
     Mechanism of knoevenagel condensation.
     Application of knoevenagel condesation.
    Definition: What is Knoevenagel
    Condensation?
     Knoevenagel condensation is a nucleophilic addition of an activated methylene compound to an
    aldehyde or ketone using an amine base (e.g., pyridine or piperidine) as a catalyst followed by a
    dehydration reaction in which a molecule of water is eliminated (condensation). The product is often
    an α,β-unsaturated carbonyl compound (enone). The Knoevenagel reaction is a particular variant of
    the aldol reaction with subsequent elimination of water. It is widely used in organic chemistry for
    C=C bond formation. The activated methylene compound should be of the form Z-CH 2-Z, where Z

    is an electron-withdrawing group. Some examples are diethyl malonate (C 2H5O-CO-CH2-CO-

    OC2H5) and malonic acid (HOOC-CH2-COOH) [1-5


    Knoevenagel condensation

    The history of this reaction goes back to 1898, when it was reported by German chemist Emil Knoevenagel.
    Examples of Knoevenagel Condensation
     Knoevenagel condensation is used in the synthesis of cinnamic acid and coumarin .
    Mechanism of Knoevenagel Condensation
    In the first step of this reaction, an amine base deprotonates the complex methylene (usually a diketone) to form a
    resonance stabilized anion (enolate). This anion then acts as a nucleophile and attaches to the carbonyl acceptor
    molecule to form an aldol product, which can undergo the dehydration reaction to form the α,β-unsaturated
    product .
     Step 1 : Deprotonation of the activated methylene by the base (piperdline) to give a carbanion
    which is resonance stabilized via enoted ion.
     Step 2 : Nucleophillic attack on the carbanion belonging to the carbonyl of the ketone by the enolate ion.
    Applications of Knoevenagel Condensation

     The product α,β-unsaturated compound is an intermediate in the formation of natural products,


    therapeutic agents, adequate chemicals, polymers having different functional groups, insecticides and
    pesticides. In commercial production, the Knoevenagel condensation is a critical step in the production
    of antimalarial drug lumefantrine, a component of Coartem. Knoevenagel’s use of primary and
    secondary amines and their salts as catalysts provided a new foundation for the study of amine
    catalysts .

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