enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. 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 .

  3. Electrophilic aromatic substitution - Wikipedia

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

    Electrophilic aromatic substitution (S E Ar) is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic nitration , aromatic halogenation , aromatic sulfonation , alkylation Friedel–Crafts ...

  4. Carbonyl α-substitution reaction - Wikipedia

    en.wikipedia.org/wiki/Carbonyl_α-substitution...

    Remarkably, ketone halogenation also occurs in biological systems, particularly in marine algae, where dibromoacetaldehyde, bromoacetone, 1, l,l -tribromoacetone, and other related compounds have been found. The halogenation is a typical α-substitution reaction that proceeds by acid catalyzed formation of an enol intermediate. [1]: 846

  5. Halogen addition reaction - Wikipedia

    en.wikipedia.org/wiki/Halogen_addition_reaction

    A halogen addition reaction is a simple organic reaction where a halogen molecule is added to the carbon–carbon double bond of an alkene functional group. [1]The general chemical formula of the halogen addition reaction is:

  6. Halogenation - Wikipedia

    en.wikipedia.org/wiki/Halogenation

    In chemistry, halogenation is a chemical reaction which introduces one or more halogens into a chemical compound. Halide -containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers , drugs . [ 1 ]

  7. Electrophilic substitution - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_substitution

    In electrophilic substitution in aromatic compounds, an atom appended to the aromatic ring, usually hydrogen, is replaced by an electrophile. The most important reactions of this type that take place are aromatic nitration, aromatic halogenation, aromatic sulfonation and acylation and alkylating Friedel-Crafts reactions. It further consists of ...

  8. Hydrohalogenation - Wikipedia

    en.wikipedia.org/wiki/Hydrohalogenation

    A hydrohalogenation reaction is the electrophilic addition of hydrogen halides like hydrogen chloride or hydrogen bromide to alkenes to yield the corresponding haloalkanes. [ 1 ] [ 2 ] [ 3 ] If the two carbon atoms at the double bond are linked to a different number of hydrogen atoms, the halogen is found preferentially at the carbon with fewer ...

  9. Hell–Volhard–Zelinsky halogenation - Wikipedia

    en.wikipedia.org/wiki/Hell–Volhard–Zelinsky...

    An example of the Hell–Volhard–Zelinsky reaction can be seen in the preparation of alanine from propionic acid.In the first step, a combination of bromine and phosphorus tribromide is used in the Hell–Volhard–Zelinsky reaction to prepare 2-bromopropionic acid, [3] which in the second step is converted to a racemic mixture of the amino acid product by ammonolysis.