Chemistry:Cyanoethylation
Cyanoethylation is a process for the attachment of CH2CH2CN group to another organic substrate. The method is used in the synthesis of organic compounds.[1] Cyanoethylation entails addition of protic nucleophiles to acrylonitrile. Typical protic nucleophiles are alcohols, thiols, and amines. Two new bonds form: C-H and C-X (X = carbon, nitrogen, sulfur, phosphorus, etc):
- [math]\displaystyle{ \mathrm{YH + H_2C{=}CH{-}CN \longrightarrow Y{-}CH_2{-}CH_2{-}CN} }[/math]
The β-carbon atom that is furthest from the nitrile group is positively polarized and therefore binds the heteroatom on the nucleophile. Acrylonitrile is a Michael acceptor.[2] The reaction is normally catalyzed by a base.[3] thumb|right|144px|[[Tris(cyanoethyl)phosphine is produced by the cyanoethylation of phosphine.[4]]] Cyanethylation is used to prepared numerous commercial chemicals. Detailed laboratory procedures are available for several variants of this reaction.
- Cyanoethylation of amines.[5][6]
- Cyanoethylation of phosphines.[7]
- Cyanoethylation of carbon nucleophiles.[8] In one commercial example, acetone is cyanoethylated to give the keto hexanenitrile, a precursor to 2-methylpyridine.[9]
An alternative method for cyanoethylation entails alkylation of the substrate with 3-chloropropionitrile.
De-cyanoethylation
Cyanoethyl is a protecting group. It is removed by treatment with base:
- RNuCH2CH2CN + OH− → RNu− + CH2=CHCN + H2O
This methodology is popular in the synthesis of oligonucleotides.[10]
References
- ↑ Eller, Karsten; Henkes, Erhard; Rossbacher, Roland; Höke, Hartmut (2000). "Ullmann's Encyclopedia of Industrial Chemistry". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a02_001.
- ↑ Smith, Michael B.; March, Jerry (2007), Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (6th ed.), New York: Wiley-Interscience, ISBN 978-0-471-72091-1, https://books.google.com/books?id=JDR-nZpojeEC&printsec=frontcover
- ↑ Hajime Kabashima, Hideshi Hattori (1998). "Cyanoethylation of Alcohols Over Solid Base Catalysts". Catalysis Today 44 (1–4): 277–283. doi:10.1016/S0920-5861(98)00200-4..
- ↑ Trofimov, Boris A.; Arbuzova, Svetlana N.; Gusarova, Nina K. (1999). "Phosphine in the synthesis of organophosphorus compounds". Russian Chemical Reviews 68 (3): 215–227. doi:10.1070/RC1999v068n03ABEH000464.
- ↑ J. Cymerman-Craig, M. Moyle (1956). "N-2-Cyanoethylaniline". Organic Syntheses 36: 6. doi:10.15227/orgsyn.036.0006.
- ↑ S. A. Heininger (1958). "3-(o-Chloroanilino)propionitrile". Organic Syntheses 38: 14. doi:10.15227/orgsyn.038.0014.
- ↑ Theodore E. Snider, Don L. Morris, K. C. Srivastava, K. D. Berlin (1973). "1-Phenyl-4-Phosphorinanone". Organic Syntheses 53: 98. doi:10.15227/orgsyn.053.0098.
- ↑ E. C. Horning A. F. Finelli (1950). "α-Phenyl-α-Carboethoxyglutaronitrile". Organic Syntheses 30: 80. doi:10.15227/orgsyn.030.0080.
- ↑ Shimizu, S.; Watanabe, N.; Kataoka, T.; Shoji, T.; Abe, N.; Morishita, S.; Ichimura, H.. "Ullmann's Encyclopedia of Industrial Chemistry". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_399.
- ↑ Liu, Qiang; Van Der Marel, Gijsbert A.; Filippov, Dmitri V. (2019). "Chemical ADP-ribosylation: Mono-ADPr-peptides and oligo-ADP-ribose". Organic & Biomolecular Chemistry 17 (22): 5460–5474. doi:10.1039/c9ob00501c. PMID 31112180.
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