Doering-Moore-Skattebøl reaction

What is Doering-Moore-Skattebøl reaction?

The Doering and LaFlamme reaction, first reported in 1958, was later refined by Moore in 1960 and Skettebøl in 1961. The resulting Doering-Moore-Skattebøl reaction, also referred to as the Doering-Moore-Skettebøl-like reaction, Doering-Moore-Skettebøl procedure, or Doering-Moore-Skettebøl method, is a two-step process that involves the addition of dibromocarbene to an olefin, followed by the treatment of the corresponding geminal cyclopropyl dibromide with alkyllithium at low temperature to prepare allene.

Doering-Moore-Skattebøl reaction - general reaction scheme
Doering-Moore-Skattebøl reaction

While the original Doering method involved treating the geminal cyclopropyl dibromide with magnesium to yield pure allene in a 16-35 % yield, or with high-surface sodium to obtain a high yield of allene with various isomers, the alkyllithiums, such as butyllithium and methyllithium, were found to be equally effective in preparing internal allenes without cyclic or acyclic isomerization.

The Doering-Moore-Skattebøl reaction involves a carbene-like intermediate, specifically a carbenoid or a free carbene, known as cyclopropylidene. These transient carbenes can either undergo ring opening to form allenes or undergo specific C-H bond insertion. At very low temperatures, a potential side product of the reaction is the alkylation product from 1-halo-1-lithiocyclopropane. Interestingly, while the conversion from antisubstituted cyclopropylidenes occurs with a high degree of stereospecificity, the syn-substituted cyclopropylidenes exhibit low stereoselectivity during the process.

The preparation of allene derivatives has been facilitated by this reaction, which has now become a widely accepted and general method.

References

  • Doering, W. von E. and LaFlamme, P. M., Tetrahedron, 1958, 2, 75
  • Moore, W. R. and Ward, H. R., J. Org. Chem., 1960, 25, 2073
  • Skattebøl, L., Tetrahedron Lett., 1961, 167
  • Doering, W. von E. and Hoffmann, A. K., J. Am. Chem. Soc., 1954, 76, 6162
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