https://de.wikipedia.org/w/api.php?action=feedcontributions&feedformat=atom&user=%7EKWikipedia - Benutzerbeiträge [de]2025-05-12T17:13:45ZBenutzerbeiträgeMediaWiki 1.44.0-wmf.28https://de.wikipedia.org/w/index.php?title=Reduktive_Aminierung&diff=196550937Reduktive Aminierung2006-10-30T03:09:05Z<p>~K: added Forster-Decker method and some minor formatting</p>
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<div>'''Reductive amination''' is a [[chemical reaction]] which involves the conversion of a [[carbonyl]] group to an [[amine]]. The carbonyl group is most commonly a [[ketone]] or an [[aldehyde]].<br />
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[[Image:ReductiveaminationOverview.png|500px|center|Reductive amination]]<br />
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==Reaction mechanism==<br />
In this [[organic reaction]], the amine first reacts with the carbonyl group, in a [[reversible reaction|reversible]] manner, to form the [[imine]] accompanied by the loss of one molecule of water by [[alkylimino-de-oxo-bisubstitution]]. The equilibrium between aldehyde/ketone and imine can be shifted toward imine formation by removal of the formed water through physical or chemical means. This intermediate [[imine]] can then be isolated and reduced with a suitable reducing agent (e.g. [[sodium borohydride]]). This is '''indirect reductive amination'''.<br />
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However, it is also possible to carry out the same reaction all in one pot, with the imine formation and reduction occurring concurrently. This is known as direct reductive amination and is carried out with reducing agents that are more reactive toward imines than ketones, such as sodium [[cyanoborohydride]] (NaBH<sub>3</sub>CN) or sodium [[triacetoxyborohydride]] (NaBH(OCOCH<sub>3</sub>)<sub>3</sub>).<br />
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This reaction is related to the [[Eschweiler-Clarke reaction]] in which amines are methylated to tertiary amines and other amine alkylation methods as the [[Mannich reaction]] and the [[Petasis reaction]].<br />
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==Scope==<br />
In industry many primary amines for example [[triethylamine]], [[Hunig's base]] or cyclopentylamine, are formed directly from ketones with a gasmixture of [[ammonia]] and [[hydrogen]] and a suitable catalyst .<br />
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The reaction depicted below is an example of an [[asymmetric reaction|asymmetric]] reductive amination of an aryl ketone and an [[aniline]].<ref>''Catalytic Asymmetric Reductive Amination of Aldehydes via Dynamic Kinetic Resolution'' Sebastian Hoffmann, Marcello Nicoletti, and Benjamin List ''[[J. Am. Chem. Soc.]]'' '''2006''', ''128(40)'', 13074 - 13075. ({{DOI|10.1021/ja065404r}})</ref><ref>In this reaction the [[reducing agent]] is an [[Hantzsch ester]] and the chiral catalyst a [[hydrogen phosphate]] of the [[BINAP]] family. [[Molecular sieve]]s remove formed water. The [[enantiomeric ratio]] is 99:1.</ref><br />
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[[Image:AsymmetricReductiveAmination.png|400px|center|Asymmetric Reductive Amination Hoffmann 2006]]<br />
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The formation of only one enantiomer from the racemic reactant is attributed to [[dynamic kinetic resolution]] because both enantiomers in the racemic imine intermediate interconvert through their common [[enamine]].<br />
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== External links ==<br />
* [http://www.organic-chemistry.org/synthesis/C1N/amines/reductiveamination.shtm Current methods for reductive amination]<br />
* Industrial Reductive amination at [http://www2.basf.de/en/intermed/nbd/technology/amination.htm?id=V00-mR-a29Q3ebw20L7 BASF]<br />
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==References==<br />
<references/><br />
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==See also==<br />
* [[Forster-Decker method]]<br />
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[[category:Organic redox reactions]]</div>~Khttps://de.wikipedia.org/w/index.php?title=Reduktive_Aminierung&diff=196550935Reduktive Aminierung2006-08-04T15:28:21Z<p>~K: sharpen cat</p>
<hr />
<div>'''Reductive amination''' is a type of [[amination]] reaction which involves the conversion of a [[carbonyl]] group to an [[amine]]. The carbonyl group is most commonly a [[ketone]] or an [[aldehyde]].<br />
<br />
<br />
In this [[organic reaction]] the amine first reacts with the carbonyl group, in a [[reversible reaction|reversible]] manner, to form the [[imine]] accompanied by the loss of one molecule of water. The equilibrium between aldehyde/ketone and imine can be shifted toward imine formation by removal of the formed water through physical or chemical means. This intermediate [[imine]] can then be isolated and reduced with a suitable reducing agent (e.g. [[sodium borohydride]]). This is '''indirect reductive amination'''.<br />
<br />
However, it is also possible to carry out the same reaction all in one pot, with the imine formation and reduction occurring concurrently. This is known as direct reductive amination and is carried out with reducing agents that are more reactive toward imines than ketones, such as sodium [[cyanoborohydride]] (NaBH<sub>3</sub>CN) or sodium [[triacetoxyborohydride]] (NaBH(OCOCH<sub>3</sub>)<sub>3</sub>).<br />
<br />
This reaction is related to the [[Eschweiler-Clarke reaction]] in which amines are methylated to tertiary amines and other amine alkylation methods as the [[Mannich reaction]] and the [[Petasis reaction]].<br />
<br />
<br />
== External links ==<br />
* [http://www.organic-chemistry.org/synthesis/C1N/amines/reductiveamination.shtm Current methods for reductive amination]<br />
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[[category:Organic redox reactions]]</div>~K