enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Electrophilic aromatic substitution - Wikipedia

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

    Compared to benzene, the rate of electrophilic substitution on pyridine is much slower, due to the higher electronegativity of the nitrogen atom. Additionally, the nitrogen in pyridine easily gets a positive charge either by protonation (from nitration or sulfonation ) or Lewis acids (such as AlCl 3 ) used to catalyze the reaction.

  3. Electrophilic substitution - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_substitution

    Electrophilic substitution reactions are chemical reactions in which an electrophile displaces a functional group in a compound, which is typically, but not always, aromatic. Aromatic substitution reactions are characteristic of aromatic compounds and are common ways of introducing functional groups into benzene rings.

  4. Substitution reaction - Wikipedia

    en.wikipedia.org/wiki/Substitution_reaction

    A substitution reaction (also known as single displacement reaction or single substitution reaction) is a chemical reaction during which one functional group in a chemical compound is replaced by another functional group. [1] Substitution reactions are of prime importance in organic chemistry.

  5. Benzene - Wikipedia

    en.wikipedia.org/wiki/Benzene

    Benzene is sufficiently nucleophilic that it undergoes substitution by acylium ions and alkyl carbocations to give substituted derivatives. Electrophilic aromatic substitution of benzene. The most widely practiced example of this reaction is the ethylation of benzene. Approximately 24,700,000 tons were produced in 1999. [73]

  6. Electrophilic halogenation - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_halogenation

    Halogenation of benzene where X is the halogen, catalyst represents the catalyst (if needed) and HX represents the protonated base. A few types of aromatic compounds, such as phenol, will react without a catalyst, but for typical benzene derivatives with less reactive substrates, a Lewis acid is required as a catalyst.

  7. Nucleophilic aromatic substitution - Wikipedia

    en.wikipedia.org/wiki/Nucleophilic_aromatic...

    The mechanism of S N 2 reaction does not occur due to steric hindrance of the benzene ring. In order to attack the C atom, the nucleophile must approach in line with the C-LG (leaving group) bond from the back, where the benzene ring lies. It follows the general rule for which S N 2 reactions occur only at a tetrahedral carbon atom.

  8. Hammett equation - Wikipedia

    en.wikipedia.org/wiki/Hammett_equation

    Consider para-disubstituted benzene p-F-C 6 H 4-Z, where Z is a substituent such as NH 2, NO 2, etc. The fluorine atom is para with respect to the substituent Z in the benzene ring. The image on the right shows four distinguished ring carbon atoms, C1, C2, C3, C4 in p-F-C 6 H 4-Z molecule. The carbon with Z is defined as C1(ipso) and ...

  9. Azo coupling - Wikipedia

    en.wikipedia.org/wiki/Azo_coupling

    In organic chemistry, an azo coupling is an reaction between a diazonium compound (R−N≡N +) and another aromatic compound that produces an azo compound (R−N=N−R’).In this electrophilic aromatic substitution reaction, the aryldiazonium cation is the electrophile, and the activated carbon (usually from an arene, which is called coupling agent), serves as a nucleophile.