Wohl–Ziegler bromination

Wohl-Ziegler bromination
Named after Alfred Wohl
Karl Ziegler
Reaction type Substitution reaction
Identifiers
Organic Chemistry Portal wohl-ziegler-reaction
RSC ontology ID RXNO:0000225

The Wohl–Ziegler reaction[1][2] is a chemical reaction that involves the allylic or benzylic bromination of hydrocarbons using an N-bromoimide and a radical initiator.[3]

Best yields are achieved with N-bromosuccinimide in carbon tetrachloride solvent. Several reviews have been published.[4][5]

In a typical setup a stoichiometric amount of N-bromosuccinimide solution and a small quantity of initiator are added to a solution of the substrate in CCl4, and the reaction mixture is stirred and heated to the boiling point. Initiation of the reaction is indicated by more vigorous boiling; sometimes the heat source may need to be removed. Once all N-bromosuccinimide (which is denser than the solvent) has been converted to succinimide (which floats on top) the reaction has finished.

References

  1. ↑ Alfred Wohl (1919). "Bromierung ungesättigter Verbindungen mit N-Brom-acetamid, ein Beitrag zur Lehre vom Verlauf chemischer Vorgänge". Berichte der deutschen chemischen Gesellschaft 52: 51–63. doi:10.1002/cber.19190520109.
  2. ↑ Ziegler, K., G. Schenck, E. W. Krockow, A. Siebert, A. Wenz, H. Weber (1942). "Die Synthese des Cantharidins". Justus Liebig's Annalen der Chemie 551: 1–79. doi:10.1002/jlac.19425510102.
  3. ↑ Greenwood, F. L.; Kellert, M. D.; Sedlak, J. (1963). "4-Bromo-2-heptene". Org. Synth.; Coll. Vol. 4, p. 108
  4. ↑ C. Djerassi (1948). "Brominations with N-Bromosuccinimide and Related Compounds. The Wohl–Ziegler Reaction". Chem. Rev. 43 (2): 271–317. doi:10.1021/cr60135a004. PMID 18887958.
  5. ↑ Horner, L; Winkelman, E. M (1959). "Neuere Methoden der präparativen organischen Chemie II 14. N-Bromsuccinimid, Eigenschaften und Reaktionsweisen Studien zum Ablauf der Substitution XV". Angew. Chem. 71: 349. doi:10.1002/ange.19590711102.


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