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[[Image:Imine-2D-skeletal.png|thumb|right|150px|The general structure of an imine]]
An '''imine''' is a [[functional group]] or [[chemical compound]] containing a [[carbon]]-[[nitrogen]] [[double bond]] <ref>March Jerry; (1985). ''Advanced Organic Chemistry reactions, mechanisms and structure'' (3rd ed.). New York: John Wiley & Sons, inc. ISBN 0-471-85472-7</ref>. Due to their diverse reactivity, imines are common substrates in a wide variety of transformations.  An imine can be synthesised by the [[nucleophilic addition]] of an [[amine]] to a [[ketone]] or [[aldehyde]] giving a [[hemiaminal]] -C(OH)(NHR)- followed by an [[elimination reaction|elimination]] of water to yield the imine. (see [[alkylimino-de-oxo-bisubstitution]] for a detailed mechanism) However, the equilibrium in this reaction usually lies in favor of the free [[carbonyl]] compound and amine, so that azeotrope distillation or use of a dehydrating agent such as [[molecular sieve]]s is required to push the reaction in favor of imine formation. 
 
Addition reactions with [[primary amine]]s give imines that are stable under an inert atmosphere.  In the presence of oxygen or water, such imines will quite readily hydrolyze or oligomerize.  However, with an [[aryl]] group or certain stabilizing [[alkyl]] [[substituent]]s on [[nitrogen]], the imine formed is stable to oxygen and water and is called a [[Schiff base]].  In contrast, imine condensations using ammonia and a carbonyl compound do not lead to stable imines - the imine formed quickly oligomerizes such as in the reaction of [[formaldehyde]] and [[ammonia]] which gives [[hexamine]] instead of the corresponding imine.  When a [[secondary amine]] is used, elimination of water from the hemiaminal leads to an [[iminium]] ion.  This iminium ion can further react to form either an [[aminal]], or [[enamine]] if there is an [[Orbital hybridization|sp<sup>3</sup>-hybridized]] carbon in the alpha position.  Addition of suitably activated carbonyl compounds to this imminium ion also leads to the corresponding [[Mannich base]].

==Imine synthesis==<!-- This section is linked from [[Organic reaction]] -->
* Condensation of amines with carbonyls in [[alkylimino-de-oxo-bisubstitution]]
* Condensation of [[carbon acid]]s with [[nitroso]] compounds
* The rearrangement of trityl N-haloamines in the [[Stieglitz rearrangement]]
* [[Dehydration]] of [[hemiaminal]]s <ref>{{OrgSynth | author = W. J. Middleton and H. D. Carlson | title = Hexafluoroacetone imine | collvol = 6 | collvolpages = 664 | year = 1988 | prep = cv6p0664}}</ref>
* By reaction of [[alkene]]s with [[hydrazoic acid]] in the [[Schmidt reaction]]

== Imine reactions ==<!-- This section is linked from [[Organic reaction]] -->
* An imine can be [[reductive amination|reduced]] to an [[amine]].
* An imine can be [[hydrolysis|hydrolysed]] with water to the corresponding [[amine]] and [[carbonyl]] compound.
* An imine reacts with an [[amine]] to an [[aminal]], see for example the synthesis of [[cucurbituril]].
* An imine reacts with [[diene]]s in the [[Aza Diels-Alder reaction]] to a tetrahydropyridine.
* An imine can be oxidized with [[meta-chloroperoxybenzoic acid]] (mCPBA) to give an oxaziridine
* An aromatic imine reacts with an [[enol ether]] to a [[quinoline]] in the [[Povarov reaction]].
* A [[tosyl]]imine reacts with an [[α,β-unsaturated carbonyl compound]] to an [[allyl]]ic [[amine]] in the [[Aza-Baylis-Hillman reaction]].
* Imines are intermediates in the alkylation of amines with formic acid in the [[Eschweiler-Clarke reaction]].
* A rearrangement in carbohydrate chemistry involving an imine is the [[Amadori rearrangement]].
* A methylene transfer reaction of an imine by an unstabilised sulphonium [[ylide]] can give an [[aziridine]] system.

==Amidates==
[[Image:Benzyl 2,2,2-trichloroacetimidate.svg|right|Benzyl 2,2,2-trichloroacetimidate.svg]]'''imidates''' (also known as imino ethers) (R-N=C(OR)R) are imines with an oxygen atom connected to carbon. These compounds find use in [[organic synthesis]] as building blocks and intermediates for example in the [[Mumm rearrangement]] and the [[Overman rearrangement]]. An example of an imidate is ''benzyl 2,2,2-trichloroacetimidate '' used to protect an [[alcohol]] as a [[benzyl ether]] with release of [[trichloroacetamide]]. 

'''Amidates''' are the corresponding [[amide]] [[enolate]]s: R-N=C(O<sup>-</sup>)R and find use as [[ligand]]s.

== See also ==
* Other functional groups with a CN double bond: [[oximes]], [[hydrazone]]s 
* Other functional groups with a CN triple bond: [[nitrile]]s, [[isonitrile]]s

==References==
{{Reflist}}
{{Functional Groups}}

[[Category:Functional groups]]

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