Birckenbach-Goubeau halogenation

What is Birckenbach-Goubeau halogenation?

The Birckenbach-Goubeau halogenation was initially documented by Birckenbach and Boubeau in 1932. This reaction involves the halogenation of aromatic compounds using halide cations that are produced from halogen and silver perchlorate AgClO4 under anhydrous conditions.

Birckenbach-Goubeau halogenation
Birckenbach-Goubeau halogenation

X = Br, I

This process can be carried out using silver acetate as the silver salt and acetic acid as the reaction medium. When this method is employed, several aryl aliphatic acids can be halogenated. Additionally, halogen cations can also be formed by combining halogen with other metal halides such as gold, copper, or mercury. For instance, when cyclohexene is iodinated using iodine and a slight excess of cuprous chloride in anhydrous ether, it produces trans-1-chloro-2-iodocyclohexane in an 80 % yield. However, if cyclohexene is subjected to iodine and silver acetate at -80 ºC, it generates 2-iodo-1-cyclohexanol acetate. Similarly, the mixture of bromine and silver acetate is a potent aromatic bromination agent and can be used to convert alkenes to bromoacetates.

This chemical process is useful in synthesizing aromatic compounds that are brominated or iodinated. It can also be utilized to produce dihaloalkanes by mixing metal halide and halogen with alkenes.

References

  • Birckenbach, L. and Goubeau, J. (1932), Pseudohalogene, XVIII. Mitteil.: Die Reaktion Silberperchlorat und Jod in organischen Medien: Eine neue Methode der Jod-Substitution. [Pseudohalogens, XVIII. The reaction of silver perchlorate and iodine in organic media: a new method of iodine substitution.] Ber. dtsch. Chem. Ges. A/B, 65: 395-401. https://doi.org/10.1002/cber.19320650307
  • Birckenbach, L., Goubeau, J. and Berninger, E. (1932), Über die Reaktion von Silbersalzen einbasischer Säuren mit Jod in Gegenwart von Cyclohexen, XXI. Mitteil.: Zur Kenntnis der Pseudohalogene. [On the reaction of silver salts of monobasic acids with iodine in the presence of cyclohexene, XXI part: On the knowledge of pseudohalogens.] Ber. dtsch. Chem. Ges. A/B, 65: 1339-1344. https://doi.org/10.1002/cber.19320650825
  • Birckenbach, L. and Goubeau, J. (1933), Über die Reaktion von Metallsalzen mit Jod und Brom in Gegenwart von Benzol (XXII. Mitteil. zur Kenntnis der Pseudohalogene). [On the reaction of metal salts with iodine and bromine in the presence of benzene (XXII. Mitteil. zur Kenntnis der Pseudohalogene).] Ber. dtsch. Chem. Ges. A/B, 66: 1280-1287. https://doi.org/10.1002/cber.19330660924
  • Birckenbach, L. and Goubeau, J. (1934), Über die Reaktion von Metallsalzen mit Jod in Gegenwart von Cyclohexen; 2) Über Zusammenhänge zwischen Bindungs-Charakter und Reaktionsfähigkeit (XXVII. Mitteil. zur Kenntnis der Pseudohalogene). [On the reaction of metal salts with iodine in the presence of cyclohexene; 2) On correlations between bond character and reactivity (XXVII. Mitteil. zur Kenntnis der Pseudohalogene).] Ber. dtsch. Chem. Ges. A/B, 67: 1420-1431. https://doi.org/10.1002/cber.19340670827
  • Birckenbach, L.; Goubeau, J. and Berninger, E., Ber., 1932, 65, 1339
Shares