In chemistry, a multi-component reaction (or MCR) is a chemical reaction where three or more compounds react to form a single product.

Examples of three component reactions:

• Alkyne trimerisation
• Biginelli reaction
• Bucherer-Bergs reaction
• Gewald reaction
• Hantzsch pyridine synthesis
• Kabachnik-Fields Reaction
• Mannich reaction
• Passerini reaction
• Pauson-Khand reaction
• Strecker amino acid synthesis

Examples of four component reactions:

• Ugi reaction
• Asinger reaction

The exact nature of this type of reaction is often difficult to assess, in collision theory a simultaneous interaction of 3 or more different molecules is less likely resulting in a low reaction rate. These reactions are more likely to involve a series of bimolecular reactions.

New MCR's are found by building a chemical library from combinatorial chemistry or by combining existing MCR's. For example, a 7-component MCR results from combining the Ugi reaction with the Asinger reaction. MCR's are an important tool in new drug discovery.

See also

• A tandem reaction is a consecutive series of intramolecular organic reactions.

References

1. Armstrong, R. W.; Combs, A. P.; Tempest, P. A.; Brown, S. D.; Keating, T. A. Acc. Chem. Res. 1996, 29, 123-131.
2. Recent progress in the chemistry of multicomponent reactions Ivar Ugi Pure Appl. Chem. 2001, 73, 187-191. (Online article)
3. The discovery of new isocyanide-based multi-component reactions Alexander Dömling Current Opinion in Chemical Biology 2000, 4, 318-323. (Online article)

External link

• Multicomponent reactions

Chemical reactions | Chemical kinetics | Components