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Cyanethylation
Minihaa: ←Created page with ''''Cyanethylation''' is a nucleophilic addition reaction. A molecule of acrylonitrile is added to a nucleophile, for example an...'
'''Cyanethylation''' is a [[Nucleophilic addition|nucleophilic addition reaction]]. A molecule of [[acrylonitrile]] is added to a [[nucleophile]], for example an [[alcohol]], [[thiol]] or an [[amine]].
:<math> \mathrm{YH + H_2C{=}CH{-}CN \longrightarrow Y{-}CH_2{-}CH_2{-}CN}</math>
Due to the mesomeric stabilization of acrylonitrile and the electron withdrawing [[Nitrile group|nitrile group]], the β-carbon atom (the carbon atom that is furthest from the nitrile group) is positively polarized and therefore acts as a [[Michael acceptor]]. This leads to an approaching of the nucleophile to the β-carbon atom, which initiates the reaction. The reaction is terminated by absorption of a proton from the [[solvent]] by the [[Intermediate product|intermediate product]]. In industrial applications, the reaction is normally [[Catalysis|catalyzed]] by a [[Base (chemistry)|base]] that polarizes or (negatively) charges the nucleophile and thus accelerates the reaction.<ref>Hajime Kabashima, Hideshi Hattori: ''Cyanoethylation of alcohols over solid base catalysts'', in: ''[[Catalysis Today]]'', Volume 44, Issues 1–4, 30. September 1998, S. 277–283, .</ref>
Cyanethylation is used especially in the industrial pharmaceutical and dye sector, since this reaction extends the nucleophile bearing molecule by three carbon atoms plus the -C≡N bond can afterwards be removed or modified by (for example) reduction. Cyanethylation is also used in technical polymerization. If cyanethylation takes place in a medium that cannot release a proton to the product at the end of the reaction, an [[Anionic polymerization|anionic polymerization]] occurs. Due to the lack of protonation, the α-carbon atom remains negatively charged, causing the individual cyanethylation products to polymerise.
== Literature ==
* Jerry March: ''Advanced Organic Chemistry. Reactions, Mechanisms, and Structure''. 3. Edition. Wiley-Interscience, New York 1985, ISBN 0-471-85472-7, S. 665.
== References ==
<references />
[[Category:Chemical reactions]]
:<math> \mathrm{YH + H_2C{=}CH{-}CN \longrightarrow Y{-}CH_2{-}CH_2{-}CN}</math>
Due to the mesomeric stabilization of acrylonitrile and the electron withdrawing [[Nitrile group|nitrile group]], the β-carbon atom (the carbon atom that is furthest from the nitrile group) is positively polarized and therefore acts as a [[Michael acceptor]]. This leads to an approaching of the nucleophile to the β-carbon atom, which initiates the reaction. The reaction is terminated by absorption of a proton from the [[solvent]] by the [[Intermediate product|intermediate product]]. In industrial applications, the reaction is normally [[Catalysis|catalyzed]] by a [[Base (chemistry)|base]] that polarizes or (negatively) charges the nucleophile and thus accelerates the reaction.<ref>Hajime Kabashima, Hideshi Hattori: ''Cyanoethylation of alcohols over solid base catalysts'', in: ''[[Catalysis Today]]'', Volume 44, Issues 1–4, 30. September 1998, S. 277–283, .</ref>
Cyanethylation is used especially in the industrial pharmaceutical and dye sector, since this reaction extends the nucleophile bearing molecule by three carbon atoms plus the -C≡N bond can afterwards be removed or modified by (for example) reduction. Cyanethylation is also used in technical polymerization. If cyanethylation takes place in a medium that cannot release a proton to the product at the end of the reaction, an [[Anionic polymerization|anionic polymerization]] occurs. Due to the lack of protonation, the α-carbon atom remains negatively charged, causing the individual cyanethylation products to polymerise.
== Literature ==
* Jerry March: ''Advanced Organic Chemistry. Reactions, Mechanisms, and Structure''. 3. Edition. Wiley-Interscience, New York 1985, ISBN 0-471-85472-7, S. 665.
== References ==
<references />
[[Category:Chemical reactions]]
February 25, 2019 at 04:13AM
