Benzidine Rearrangement

Benzidine Rearrangement

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  • General Characteristics

Under acidic conditions, 1,2-diphenylhydrazines are known to rearrange into 4,4’-diaminobiphenyls (benzidines).

  • General References

  • Hofmann, A. W. Proc. Roy. Soc. London 186312, 576.
  • Jacobson, P. et al. Ber.1893, 26, 688.


  • Reaction Mechanism

The rearrangement is thought to proceed via concerted [5,5]-sigmatropic rearrangement. (Ref: J. Am. Chem. Soc. 1981103, 955; J. Am. Chem. Soc. 1982104, 2501; J. Am. Chem. Soc. 1984106, 7077.) benzidine_rearr_2.gif

When the para position is substituted, rearrangement occurs at the ortho position ([3,3]-sigmatropic rearrangement, the diaza-Cope rearrangement).

  • Examples

In 2013, List and Kürti independently reported asymmetric benzidine rearrangement catalyzed by chiral phosphoric acids, demonstrating the synthesis of 1,1’-binaphthyl-2,2’-diamine (BINAM) in impressively high yields and enantioselectivities.[1]


  • Experimental Procedure

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  • References

[1] (a) Kanta, C.; Fabio, D.; Pesciaioli, F.;List, B.  Angew. Chem. Int. Ed. 2013, 52, 9293. DOI: 10.1002/anie.201304039 (b) Li, G-Q.; Gao, H.; Keene, C.; Devonas M.; Ess, D.H.; Kürti, L.  J. Am. Chem. Soc.. 2013, 135, 7414 DOI: 10.1021/ja401709k

  • Related Reactions

  • Related Books

  • External Links

Benzidine – Wikipedia

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