Amination is the process by which an amine group is introduced into an organic molecule. This type of reaction is important because organonitrogen compounds are pervasive.
Reactions
Aminase enzymes
Enzymes that
catalysis this reaction are termed
aminases. Amination can occur in a number of ways including reaction with
ammonia or another
amine such as an
alkylation, reductive amination and the
Mannich reaction.
Acid-catalysed hydroamination
Many alkyl amines are produced industrially by the amination of alcohols using ammonia in the presence of
solid acid catalysts. Illustrative is the production of
tert-butylamine:
- NH3 + CH2=C(CH3)2 → H2NC(CH3)3
The
Ritter reaction of
isobutene with
hydrogen cyanide is not useful in this case because it produces too much waste.
Electrophilic amination
Usually, the amine reacts as the
nucleophile with another organic compound acting as the
electrophile. This sense of reactivity may be reversed for some electron-deficient amines, including
,
,
, and other N–O substrates. When the amine is used as an electrophile, the reaction is called electrophilic amination. Electron-rich organic substrates that may be used as nucleophiles for this process include
and
.
Miscellaneous methods
Alpha hydroxy acids can be converted into amino acids directly using aqueous ammonia solution, hydrogen gas and a heterogeneous metallic
ruthenium catalyst.
[ Deng, Weiping, et al. "Catalytic amino acid production from biomass-derived intermediates." Proceedings of the National Academy of Sciences 115.20 (2018): 5093-5098. ]
Metal-catalyzed hydroamination
In
hydroamination, amines add to
.
[Liangbin Huang, Matthias Arndt, Käthe Gooßen, Heinrich Heydt, and Lukas J. Gooßen "Late Transition Metal-Catalyzed Hydroamination and Hydroamidation" Chem. Rev., 2015, 115 (7), pp 2596–2697. ] When substituted amines add, the result is alkene carboamination.
See also
