Overman Rearrangement

Overman Rearrangement

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  • General Characteristics

The trichloroacetimidates of allylic alcohols, prepared using trichloroacetonitrile, undergo thermal or catalyzed [3,3]-sigmatropic rearrangement, which is referred to as the Overman rearrangement. This reaction is an effective option to prepare allylic amines including synthetically challenging α-quaternary amines.

  • General References

  • Overman, L. E. J. Am. Chem. Soc. 197496, 597. DOI: 10.1021/ja00809a054
  • Overman, L. E. J. Am. Chem. Soc. 197698, 2901. DOI: 10.1021/ja00426a038
  • Overman, L. E. Acc. Chem. Res. 1980, 13, 218. DOI: 10.1021/ar50151a005
  • Nishikawa, T.; Asai, M.; Ohyabu, N.; Isobe, M. J. Org. Chem.1998, 63, 188. DOI: 10.1021/jo9713924
  • Reaction Mechanism

The rearrangement is believed to go through a six-membered chair transition state similar to the Claisen and other rearrangements.

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  • Examples

An application in the total synthesis of pancratistatin.[1]

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The COP (cobalt oxazoline palladacycle) catalyst was used to render the rearrangement enantioselective.[2]

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  • Experimental Procedure

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  • References

[1] Danishefsky, S. J.; Lee, J. Y. J. Am. Chem. Soc. 1989111, 4829. DOI: 10.1021/ja00195a039
[2] (a) Anderson, C. E.; Overman, L. E. J. Am. Chem. Soc. 2003, 125, 12412. DOI: 10.1021/ja037086r
(b) Anderson, C. E.; Overman, L. E. Org. Synth. 200582, 134. [website]

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