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  2. Electron-withdrawing group - Wikipedia

    en.wikipedia.org/wiki/Electron-withdrawing_group

    An electron-withdrawing group (EWG) is a group or atom that has the ability to draw electron density toward itself and away from other adjacent atoms. [1] This electron density transfer is often achieved by resonance or inductive effects.

  3. Captodative effect - Wikipedia

    en.wikipedia.org/wiki/Captodative_effect

    Delocalizing the radical ion stabilizes the transition state structure. As a result, the energy of activation decreases, enhancing the rate of the overall reaction. According to the captodative effect, the rate of a reaction is the greatest when both the EDG and EWG are able to delocalize the radical ion in the transition state structure. [7]

  4. Electrophilic aromatic directing groups - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_aromatic...

    The EWG removes electron density from a π system, making it less reactive in this type of reaction, [2] [3] and therefore called deactivating groups. EDGs and EWGs also determine the positions (relative to themselves) on the aromatic ring where substitution reactions are most likely to take place.

  5. Electronic effect - Wikipedia

    en.wikipedia.org/wiki/Electronic_effect

    An electric effect influences the structure, reactivity, or properties of a molecule but is neither a traditional bond nor a steric effect. [1] In organic chemistry, the term stereoelectronic effect is also used to emphasize the relation between the electronic structure and the geometry (stereochemistry) of a molecule.

  6. Inductive effect - Wikipedia

    en.wikipedia.org/wiki/Inductive_effect

    In Organic chemistry, the inductive effect in a molecule is a local change in the electron density due to electron-withdrawing or electron-donating groups elsewhere in the molecule, resulting in a permanent dipole in a bond. [1] It is present in a σ (sigma) bond, unlike the electromeric effect which is present in a π (pi) bond.

  7. Vinylogy - Wikipedia

    en.wikipedia.org/wiki/Vinylogy

    Vinylogous reactions are believed to occur when orbitals of the double bonds of the vinyl group and of an attached electron-withdrawing group (EWG; the π orbitals) are aligned and so can overlap and mix (i.e., are conjugated). Electron delocalization enables the EWG to receive electron density through participation of the conjugated system.

  8. Nitro compound - Wikipedia

    en.wikipedia.org/wiki/Nitro_compound

    Chloramphenicol is a rare example of a naturally occurring nitro compound. At least some naturally occurring nitro groups arose by the oxidation of amino groups. [17] 2-Nitrophenol is an aggregation pheromone of ticks. Examples of nitro compounds are rare in nature. 3-Nitropropionic acid found in fungi and plants .

  9. Horner–Wadsworth–Emmons reaction - Wikipedia

    en.wikipedia.org/wiki/Horner–Wadsworth–Emmons...

    The Horner–Wadsworth–Emmons (HWE) reaction is a chemical reaction used in organic chemistry of stabilized phosphonate carbanions with aldehydes (or ketones) to produce predominantly E-alkenes. [1] The Horner–Wadsworth–Emmons reaction. In 1958, Leopold Horner published a modified Wittig reaction using phosphonate-stabilized carbanions.