Information about Hofmann Elimination
Hofmann elimination (also known as exhaustive methylation) is a process where an amine is reacted to create a tertiary amine and an alkene by treatment with excess methyl iodide followed by treatment with silver oxide, water, and heat (Fig. 1).
After the first step, a quartenary ammonium iodide salt is created as can be seen in the exact reaction mechanism in Figure 2. The major alkene product is the least substituted and generally the least stable, an observation known as the Hofmann rule. This is in direct contrast to normal elimination reactions where the more substituted, stable product is dominant (Zaitsev's rule).
The reaction is named after its discoverer: August Wilhelm von Hofmann.
The ammonium cation is a positively charged polyatomic cation of the chemical formula NH4+. It has a molecular mass of 18.
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After the first step, a quartenary ammonium iodide salt is created as can be seen in the exact reaction mechanism in Figure 2. The major alkene product is the least substituted and generally the least stable, an observation known as the Hofmann rule. This is in direct contrast to normal elimination reactions where the more substituted, stable product is dominant (Zaitsev's rule).
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Figure 2: Hofmann elimination mechanism
The reaction is named after its discoverer: August Wilhelm von Hofmann.
See also
- The Hofmann rearrangement or Hofmann degradation
- The Emde degradation.
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Methylation is a term used in the chemical sciences to denote the attachment or substitution of a methyl group on various substrates. This term is commonly used in chemistry, biochemistry, and the biological sciences.
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Amines are organic compounds and a type of functional group that contain nitrogen as the key atom. Structurally amines resemble ammonia, wherein one or more hydrogen atoms are replaced by organic substituents such as alkyl and aryl groups.
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alkene, olefin, or olefine is an unsaturated chemical compound containing at least one carbon-to-carbon double bond. The simplest alkenes, with only one double bond and no other functional groups, form a homologous series of hydrocarbons with the general formula
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In chemistry, a methyl group is a hydrophobic alkyl functional group derived from methane (CH4). It has the formula -CH3 and is very often abbreviated as -Me in the structure of a molecule. This hydrocarbon unit can be found in many organic compounds.
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iodide ion is an iodine atom with a −1 charge. Compounds with iodine in formal oxidation state −1 are called iodides. This can include ionic compounds such as caesium iodide or covalent compounds such as carbon tetraiodide.
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Silver (IPA: /ˈsɪlvə(ɹ)/) is a chemical element with the symbol Ag (Latin: argentum) and atomic number 47.
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An oxide is a chemical compound containing at least one oxygen atom and other elements. Most of the earth's crust consists of oxides. Oxides result when elements are oxidized by air.
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Water is a common chemical substance that is essential to all known forms of life.[1] In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor.
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- Ammonium is also an old name for the Siwa Oasis in western Egypt.
The ammonium cation is a positively charged polyatomic cation of the chemical formula NH4+. It has a molecular mass of 18.
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iodide ion is an iodine atom with a −1 charge. Compounds with iodine in formal oxidation state −1 are called iodides. This can include ionic compounds such as caesium iodide or covalent compounds such as carbon tetraiodide.
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In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical change occurs.
Although only the net chemical change is directly observable for most chemical reactions, experiments can often be designed that suggest the
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Although only the net chemical change is directly observable for most chemical reactions, experiments can often be designed that suggest the
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An elimination reaction is a type of organic reaction in which two substituents are removed from a molecule in either a one or two-step mechanism [1]. Either the unsaturation of the molecule increases (as in most organic elimination reactions) or the valence of an atom
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In chemistry, Zaitsev's rule, Saytzeff's rule or Saytsev's rule named after Alexander Mikhailovich Zaitsev (number of different spellings due to the name being transliterated from Russian) is a rule that states that if more than one alkene can be formed by an
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August Wilhelm von Hofmann
August Wilhelm von Hofmann
Born March 8 1818
Giessen, Germany
Died May 5 1892 (aged 74)
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August Wilhelm von Hofmann
Born March 8 1818
Giessen, Germany
Died May 5 1892 (aged 74)
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The Hofmann rearrangement is the organic reaction of a primary amide to a primary amine with one fewer carbon atom.[1][2][3]
The reaction of bromine with sodium hydroxide forms sodium hypobromite in situ, which transforms the primary amide
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The reaction of bromine with sodium hydroxide forms sodium hypobromite in situ, which transforms the primary amide
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The Emde degradation (also called Emde-reaction or Emde-reduction) is a method for the reduction of a quaternary ammonium cation to a tertiary amine with sodium amalgam [1] [2] [3]
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