Favorskii-Babayan reaction

What is Favorskii-Babayan reaction?

The Favorskii reaction was discovered by Favorskii in 1905 and further developed by Babayan in 1939. It involves the use of anhydrous KOH or NaOH as a base promoter or catalyst to carry out the ethynylation of aldehydes and ketones, resulting in the production of secondary or tertiary acetylenic alcohols or glycols. This reaction is commonly referred to as the Favorskii-Babayan reaction or Favorskii reaction.

Favorskii-Babayan reaction - general reaction scheme - Favorskii reaction
Favorskii-Babayan reaction

Previous studies have proposed that the reaction could occur through the coupling of potassium acetylide with carbonyl compounds or by reacting acetylene with the adduct formed from the ketone and KOH. However, recent experimental findings suggest that the reaction involves the formation of a complex between potassium hydroxide and acetylene, rather than potassium acetylide, in liquid ammonia. This complex then reacts with carbonyl compounds to produce acetylenic alcohols, with ammonia serving as a co-catalyst. The evidence supporting this includes the observation that the formed dry complex decomposes under low pressure and high temperature, the absence of stretch peaks for the carbon-carbon triple bond and C−H bond on infrared spectra, and the strong association of the complex with an electron-donating solvent such as ammonia or diisopropyl ether. The resulting acetylenic alcohols have potential uses as nonionic surfactants.

While KOH is the most effective promoter for this reaction, NaOH can also be used, albeit with lower efficiency. LiOH, on the other hand, is almost inert. It should also be noted that the Favorskii-Babayan reaction can occur in the presence of a catalytic amount of KOH.

References

  • A. E. Favorskii, J. Russ. Phys. Chem. Soc. 37, 643 (1905)
  • A. E. Favorskii, Chem. Zentr. 1905, II, 1018
  •  Babayan, A.; Akopyan, B. and Gyuli-Kevhyan, R., J. Gen. Chem. (USSR) 9, 1631 (1939)
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