Amination is the process by which an

amine In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent suc ...

group is introduced into an organic

molecule A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioch ...

. This type of reaction is important because organonitrogen compounds are pervasive.

Reactions

;Aminase enzymes Enzymes that catalyse this reaction are termed aminases. Amination can occur in a number of ways including reaction with

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...

or another

such as an

alkylation Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effecting al ...

reductive amination Reductive amination (also known as reductive alkylation) is a form of amination that involves the conversion of a carbonyl group to an amine via an intermediate imine. The carbonyl group is most commonly a ketone or an aldehyde. It is considered t ...

and the

Mannich reaction In organic chemistry, the Mannich reaction is a three-component organic reaction that involves the amino alkylation of an acidic proton next to a carbonyl () functional group by formaldehyde () and a primary or secondary amine () or ammonia (). ...

. ;Acid-catatlyzed hydroamination Many alkyl amines are produced industrially by the amination of alcohols using ammonia in the presence of

solid acid Solid is one of the four fundamental states of matter (the others being liquid, gas, and plasma). The molecules in a solid are closely packed together and contain the least amount of kinetic energy. A solid is characterized by structural r ...

catalysts. Illustrative is the production of ''tert''-butylamine: :NH₃ + CH₂=C(CH₃)₂ → H₂NC(CH₃)₃ ;Ritter reaction The

Ritter reaction The Ritter reaction is a chemical reaction that transforms a nitrile into an ''N''-alkyl amide using various electrophilic alkylating reagents. The original reaction formed the alkylating agent using an alkene in the presence of a strong acid. M ...

isobutene Isobutylene (or 2-methylpropene) is a hydrocarbon with the chemical formula . It is a four-carbon branched alkene (olefin), one of the four isomers of butylene. It is a colorless flammable gas, and is of considerable industrial value. Produ ...

with

hydrogen cyanide Hydrogen cyanide, sometimes called prussic acid, is a chemical compound with the formula HCN and structure . It is a colorless, extremely poisonous, and flammable liquid that boils slightly above room temperature, at . HCN is produced on an in ...

is not useful in this case because it produces too much waste. In electrophilic amination, the amine as the

nucleophile In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are ...

react with another organic compound as the

electrophile In chemistry, an electrophile is a chemical species that forms bonds with nucleophiles by accepting an electron pair. Because electrophiles accept electrons, they are Lewis acids. Most electrophiles are positively charged, have an atom that carri ...

. This sense of reactivity may be reversed for some electron-deficient amines, including

oxaziridine An oxaziridine is an organic molecule that features a three-membered heterocycle containing oxygen, nitrogen, and carbon. In their largest application, oxaziridines are intermediates in the industrial production of hydrazine. Oxaziridine deri ...

s, hydroxylamines,

oxime In organic chemistry, an oxime is a organic compound belonging to the imines, with the general formula , where R is an organic side-chain and R’ may be hydrogen, forming an aldoxime, or another organic group, forming a ketoxime. O-substitut ...

s, and other N–O substrates. When the amine is used as an

, the reaction is called electrophilic amination. Electron-rich organic substrates that may be used as nucleophiles for this process include carbanions and

enolate In organic chemistry, enolates are organic anions derived from the deprotonation of carbonyl () compounds. Rarely isolated, they are widely used as reagents in the synthesis of organic compounds. Bonding and structure Enolate anions are electr ...

s. ;Miscellaneous methods Alpha hydroxy acids can be converted into amino acids directly using aqueous ammonia solution, hydrogen gas and a heterogeneous metallic

ruthenium Ruthenium is a chemical element with the symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most other chemicals ...

catalyst. ;Metal-catalyzed hydroamination In

hydroamination In organic chemistry, hydroamination is the addition of an bond of an amine across a carbon-carbon multiple bond of an alkene, alkyne, diene, or allene. In the ideal case, hydroamination is atom economical and green. Amines are common in fin ...

, amines add to

alkene In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, a ...

s.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.

References

{{Reflist Organic reactions

Reactions

See also

References