Corey-Fuchs reaction

The Corey-Fuchs reaction is a series of chemical reactions designed to transform an aldehyde into an alkyne.^[1][2][3] The reaction is named after its discoverers, American chemists Elias James Corey and Philip L. Fuchs.

Additional recommended knowledge

Recognize and detect the effects of electrostatic charges on your balance

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By suitable choice of base, it is often possible to stop the reaction at the 1-bromoalkyne, a useful functional group for further transformation.

Reaction Mechanism

The Corey-Fuchs reaction is based on a special case of the Wittig Reaction, where the phosphorus ylide is formed from dibromocarbene. This carbene is generated in situ from the reaction of Triphenylphosphine and carbon tetrabromide.

Triphenylphosphine then attacks the nascent carbene to form the reactive ylide. This ylide undergoes a Wittig Reaction when exposed to an aldehyde.

The dibromoalkene reacts with butyllithium via deprotonation. Next, the resulting species ejects bromide through an beta-elimination pathway to produce the alkyne.

References

1. ^  Corey, E. J.; Fuchs, P. L. Tetrahedron Lett. 1972, 36, 3769-3772.
2. ^  Mori, M.; Tonogaki, K.; Kinoshita, A. Organic Syntheses, Vol. 81, p.1 (2005). (Article)
3. ^  Marshall, J. A.; Yanik, M. M.; Adams, N. D.; Ellis, K. C.; Chobanian, H. R. Organic Syntheses, Vol. 81, p.157 (2005). (Article)

See also

• Fritsch-Buttenberg-Wiechell rearrangement
• Seyferth-Gilbert homologation
• Wittig reaction