TheGattermann reaction (also known as theGattermann formylation and theGattermann salicylaldehyde synthesis) is a chemical reaction in which aromatic compounds areformylated by a mixture ofhydrogen cyanide (HCN) andhydrogen chloride (HCl) in the presence of aLewis acidcatalyst such asaluminium chloride (AlCl3).[1] It is named for the German chemistLudwig Gattermann[2] and is similar to theFriedel–Crafts reaction.
| Gattermann formylation | |
|---|---|
| Named after | Ludwig Gattermann |
| Reaction type | Substitution reaction |
| Identifiers | |
| RSC ontology ID | RXNO:0000139 |
Modifications have shown that it is possible to usesodium cyanide orcyanogen bromide in place of hydrogen cyanide.[3]
The reaction can be simplified by replacing the HCN/AlCl3 combination withzinc cyanide.[4] Although it is also highly toxic, Zn(CN)2 is a solid, making it safer to work with than gaseous HCN.[5] The Zn(CN)2 reacts with the HCl to form the key HCN reactant and Zn(Cl)2 that serves as the Lewis-acid catalystin-situ. An example of the Zn(CN)2 method is the synthesis ofmesitaldehyde frommesitylene.[6]
Gattermann–Koch reaction
edit| Gattermann–Koch formylation | |
|---|---|
| Named after | Ludwig Gattermann Julius Arnold Koch |
| Reaction type | Substitution reaction |
TheGattermann–Koch reaction, named after the German chemists Ludwig Gattermann andJulius Arnold Koch,[7] is a variant of the Gattermann reaction in whichcarbon monoxide (CO) is used instead of hydrogen cyanide.[8]
Unlike the Gattermann reaction, this reaction is not applicable tophenol and phenolether substrates.[5] Although the highly unstable formyl chloride was initially postulated as an intermediate, formyl cation (i.e., protonated carbon monoxide), [HCO]+, is now thought to react directly with the arene without the initial formation of formyl chloride.[9] Additionally, when zinc chloride is used as the Lewis acid instead of aluminum chloride for example, or when the carbon monoxide is not used at high pressure, the presence of traces ofcopper(I) chloride ornickel(II) chloride co-catalyst is often necessary. The transition metal co-catalyst may server as a "carrier" by first reacting with CO to form a carbonyl complex, which is then transformed into the active electrophile.[10]
See also
editReferences
edit- ^Smith, Michael B.;March, Jerry (2007),Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (6th ed.), New York: Wiley-Interscience, p. 725,ISBN 978-0-471-72091-1
- ^Gattermann, L.; Berchelmann, W. (1898)."Synthese aromatischer Oxyaldehyde".Berichte der deutschen chemischen Gesellschaft.31 (2):1765–1769.doi:10.1002/cber.18980310281.
- ^Karrer, P. (1919). "Über Oxycarbonylverbindungen I. Eine neue Synthese von" [Hydroxycarbonyl compounds. I. A new synthesis of hydroxyaldehydes].Helvetica Chimica Acta (in German).2 (1):89–94.doi:10.1002/hlca.19190020109.
- ^Adams R.; Levine, I. (1923). "Simplification of the Gattermann Synthesis of Hydroxy Aldehydes".J. Am. Chem. Soc.45 (10):2373–77.doi:10.1021/ja01663a020.
- ^abAdams, Roger (1957).Organic Reactions, Volume 9. New York: John Wiley & Sons, Inc. pp. 38 & 53–54.doi:10.1002/0471264180.or009.02.ISBN 9780471007265.
{{cite book}}:ISBN / Date incompatibility (help) - ^Fuson, R. C.; Horning, E. C.; Rowland, S. P.; Ward, M. L. (1955). "Mesitaldehyde".Organic Syntheses.doi:10.15227/orgsyn.023.0057;Collected Volumes, vol. 3, p. 549.
- ^Gattermann, L.;Koch, J. A. (1897)."Eine Synthese aromatischer Aldehyde".Chemische Berichte.30 (2):1622–1624.doi:10.1002/cber.18970300288.
- ^Li, Jie Jack (2003).Name Reactions: A Collection of Detailed Reaction Mechanisms(available onGoogle Books) (2nd ed.).Springer. p. 157.ISBN 3-540-40203-9.
- ^Kurti, Laszlo. (2005).Strategic Applications of Named Reactions in Organic Synthesis : Background and Detailed Mechanisms. Czako, Barbara. Burlington: Elsevier Science.ISBN 978-0-08-057541-4.OCLC 850164343.
- ^Dilke, M. H.; Eley, D. D. (1949)."550. The Gattermann–Koch reaction. Part II. Reaction kinetics".J. Chem. Soc.:2613–2620.doi:10.1039/JR9490002613.ISSN 0368-1769.