Tishchenko reaction

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| Name = Tishchenko reaction

| Type = Organic redox reaction

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The Tishchenko reaction is an organic chemical reaction that involves disproportionation of an aldehyde in the presence of an alkoxide. The reaction is named after Russian organic chemist Vyacheslav Tishchenko, who discovered that aluminium alkoxides are effective catalysts for the reaction.{{cite journal|doi=10.1246/cl.2006.824|title=The Tishchenko Reaction: A Classic and Practical Tool for Ester Synthesis|journal=Chemistry Letters|volume=35|issue=8|pages=824–829|year=2006|last1=Seki|first1=Tsunetake|last2=Nakajo|first2=Tetsuo|last3=Onaka|first3=Makoto}}{{cite journal|doi=10.1002/ejoc.200600258|title=Direct Asymmetric Aldol-Tishchenko Reaction|journal=European Journal of Organic Chemistry|volume=2006|issue=21|pages=4779–4786|year=2006|last1=Mlynarski|first1=Jacek}}

{{cite journal|doi=10.1016/S0926-860X(01)00839-0|title=Solid base catalysts: Generation of basic sites and application to organic synthesis|journal=Applied Catalysis A: General|volume=222|issue=1–2|pages=247–259|year=2001|last1=Hattori|first1=Hideshi}}

In the related Cannizzaro reaction, the base is sodium hydroxide and then the oxidation product is a carboxylic acid and the reduction product is an alcohol.

History

The reaction involving benzaldehyde was discovered by Claisen using sodium benzylate as base. The reaction produces benzyl benzoate.{{cite journal| last1 = Kamm | first1 = O. | last2 = Kamm | first2 = W. F. | title = Benzyl benzoate | journal = Organic Syntheses | year = 1922 | volume = 2 | pages = 5 | doi = 10.15227/orgsyn.002.0005 }}

File:Tishchenko reaction.svg

Enolizable aldehydes are not amenable to Claisen's conditions. Vyacheslav Tishchenko discovered that aluminium alkoxides allowed the conversion of enolizable aldehydes to esters.

Examples

The Tishchenko reaction of acetaldehyde gives the commercially important solvent ethyl acetate. The reaction is catalyzed by aluminium alkoxides.{{cite encyclopedia |first1=Marc |last1=Eckert |first2=Gerald |last2=Fleischmann |first3=Reinhard |last3=Jira |first4=Hermann M. |last4=Bolt |first5=Klaus |last5=Golka | title=Acetaldehyde | encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry | doi=10.1002/14356007.a01_031.pub2 | publisher=Wiley | date=15 December 2006|isbn=3527306730 }}
The Tishchenko reaction is used to obtain isobutyl isobutyrate, a specialty solvent.{{cite encyclopedia |first1=Boy |last1=Cornils |first2=Richard W. |last2=Fischer |first3=Christian |last3=Kohlpaintner | title=Butanals | encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry | publisher=Wiley | date=15 September 2000 | doi=10.1002/14356007.a04_447|isbn=3527306730 }}
Hydroxypivalic acid neopentyl glycol ester is produced by a Tishchenko reaction from hydroxypivaldehyde in the presence of a basic catalyst (e.g., aluminium oxide).{{cite encyclopedia |first1=Peter |last1=Werle |first2=Marcus |last2=Morawietz | title=Alcohols, Polyhydric | encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry | publisher=Wiley | date=15 June 2000 | doi=10.1002/14356007.a01_305|isbn=3527306730 }}
The Tishchenko reaction of paraformaldehyde in the presence of aluminum methylate or magnesium methylate forms methyl formate.{{cite encyclopedia |first1=Günther |last1=Reuss |first2=Walter |last2=Disteldorf |first3=Armin Otto |last3=Gamer |first4=Albrecht |last4=Hilt | title=Formaldehyde | encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry | publisher=Wiley | date=15 June 2000 | doi=10.1002/14356007.a11_619|isbn=3527306730 }}
Paraformaldehyde reacts with boric acid to form methyl formate.{{cite journal | author = Paul R. Stapp | journal = Journal of Organic Chemistry | year = 1973 | volume = 38 | issue = 7 | pages = 1433–1434 | doi = 10.1021/jo00947a049 | title = Boric acid catalyzed Tishchenko reactions}} The key step in the reaction mechanism for this reaction is a 1,3-hydride shift in the hemiacetal intermediate formed from two successive nucleophilic addition reactions, the first one from the catalyst. The hydride shift regenerates the alkoxide catalyst.

Tishchenko reaction

History

Examples

See also

References

Further reading