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  2. Halogen addition reaction - Wikipedia

    en.wikipedia.org/wiki/Halogen_addition_reaction

    The reaction mechanism for an alkene bromination can be described as follows. In the first step of the reaction, a bromine molecule approaches the electron-rich alkene carbon–carbon double bond. The bromine atom closer to the bond takes on a partial positive charge as its electrons are repelled by the electrons of the double bond.

  3. Halogenation - Wikipedia

    en.wikipedia.org/wiki/Halogenation

    The addition of halogens to alkenes proceeds via intermediate halonium ions. In special cases, such intermediates have been isolated. [5] Bromination is more selective than chlorination because the reaction is less exothermic. Illustrative of the bromination of an alkene is the route to the anesthetic halothane from trichloroethylene: [6]

  4. 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 ...

  5. Electrophilic halogenation - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_halogenation

    In organic chemistry, an electrophilic aromatic halogenation is a type of electrophilic aromatic substitution. This organic reaction is typical of aromatic compounds and a very useful method for adding substituents to an aromatic system.

  6. 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

  7. Free-radical halogenation - Wikipedia

    en.wikipedia.org/wiki/Free-radical_halogenation

    In organic chemistry, free-radical halogenation is a type of halogenation. This chemical reaction is typical of alkanes and alkyl -substituted aromatics under application of UV light . The reaction is used for the industrial synthesis of chloroform (CHCl 3 ), dichloromethane (CH 2 Cl 2 ), and hexachlorobutadiene .

  8. Haloform reaction - Wikipedia

    en.wikipedia.org/wiki/Haloform_reaction

    In chemistry, the haloform reaction (also referred to as the Lieben haloform reaction) is a chemical reaction in which a haloform (CHX 3, where X is a halogen) is produced by the exhaustive halogenation of an acetyl group (R−C(=O)CH 3, where R can be either a hydrogen atom, an alkyl or an aryl group), in the presence of a base.

  9. Halonium ion - Wikipedia

    en.wikipedia.org/wiki/Halonium_ion

    Many halonium ions have a three-atom cyclic structure, similar to that of an epoxide, resulting from the formal addition of a halogenium ion X + to a C=C double bond, as when a halogen is added to an alkene. [1] The formation of 5-membered halonium ions (e.g., chlorolanium, bromolanium ions) via neighboring group participation is also well ...