The Tishchenko Reaction is a disproportionation reaction that allows the preparation of esters from two equivalents of an aldehyde.
Mechanism of the Tishchenko Reaction
The aluminium alkoxide acts as a Lewis acid to coordinate with one molecule of the aldehyde, and to facilitate the addition of a second equivalent of aldehyde, generating a hemiacetal intermediate:
This species undergoes an intramolecular 1,3-hydride shift that results in the production of the aluminium-coordinated ester.
A potential side reaction is the involvement of one of the alkoxide groups from the catalyst:
This can be minimised, if the reaction is conducted at low temperatures and low catalyst loadings.
The Thiolate-Catalyzed Intermolecular Crossed Tishchenko Reaction: Highly Chemoselective Coupling of Two Different Aromatic Aldehydes
S. P. Curran, S. J. Connon, Angew. Chem. Int. Ed., 2012, 51, 10866-10870.
Lithium Bromide as a Flexible, Mild, and Recyclable Reagent for Solvent-Free Cannizzaro, Tishchenko, and Meerwein-Ponndorf-Verley Reactions
M. M. Mojtahedi, E. Akbarzadeh, R. Sharifi, M. S. Abaee, Org. Lett., 2007, 9, 2791-2793.
Catalytic Meerwein-Ponndorf-Verley (MPV) and Oppenauer (OPP) Reactions: Remarkable Acceleration of the Hydride Transfer by Powerful Bidentate Aluminum Alkoxides
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