The Hunsdiecker reaction (also called the Borodin reaction after Alexander Borodin) is the organic reaction of silver salts of carboxylic acids with halogens to give organic halides.

Several reviews have been published.

Mercuric oxide will also effect this transformation.

Reaction mechanism

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The reaction mechanism of the Hunsdiecker reaction is believed to involved organic radical intermediates. The silver salt of the carboxylic acid 1 will quickly react with bromine to form intermediate 2. Formation of the diradical pair 3 allows for radical decarboxylation to form the diradical pair 4, which will quickly recombine to form the desired organic halide 5.

References

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1. Hunsdiecker, C. et al. U.S. Patent # 2,176,181.
2. Hunsdiecker, H.; Hunsdiecker, C. Ber. 1942, 75, 291.
3. Borodin, A. Ann. 1861, 119, 121.
4. Allen, C. F. H.; Wilson, C. V. Organic Syntheses, Coll. Vol. 3, p.578 (1955); Vol. 26, p.52 (1946). (Article)
5. Johnson, R. G.; Ingham, R. K. Chem. Rev. 1956, 56, 219. (Review)
6. Wilson, C. V. Org. React. 1957, 9, 341. (Review)
7. Meek, J. S.; Osuga, D. T. Organic Syntheses, Coll. Vol. 5, p.126 (1973); Vol. 43, p.9 (1963). (Article)
8. Lampman, G. M.; Aumiller, J. C. Organic Syntheses, Coll. Vol. 6, p.179 (1988); Vol. 51, p.106 (1971). (Article)

See also

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• Barton-McCombie deoxygenation
• Kochi reaction
• Simonini reaction

Organic reactions