Overman rearrangement explained

The Overman rearrangement is a chemical reaction that can be described as a Claisen rearrangement of allylic alcohols to give allylic trichloroacetamides through an imidate intermediate.^{[1] [2] [3]} The Overman rearrangement was discovered in 1974 by Larry Overman.^[4]

The [3,3]-sigmatropic rearrangement is diastereoselective and requires heating or the use of Hg(II) or Pd(II) salts as catalysts.^[5] The resulting allylamine structures can be transformed into many chemically and biologically important natural and un-natural amino acids (like (1-adamantyl)glycine).^[6]

The Overman rearrangement may also be used for asymmetric synthesis.^{[7] [8]}

See also

• Pinner reaction

Further reading

• Isobe . M. . etal . 1990 . Synthetic studies on (−)-tetrodotoxin (3) nitrogenation through overman rearrangement and guanidine ring formation. Tetrahedron Lett. . 31 . 23. 3327 . 10.1016/s0040-4039(00)89056-5 .
• Allmendinger . T. . etal . 1990 . Fluoroolefin dipeptide isosteres -II.. . 31 . 50. 7301 . 10.1016/s0040-4039(00)88549-4 .
• Nishikawa . T. . Asai . M. . Ohyabu . N. . Isobe . M. . 1998 . Improved Conditions for Facile Overman Rearrangement(1). . 63 . 1. 188–192 . 11674062 . 10.1021/jo9713924 .

Notes and References

1. A general method for the synthesis of amines by the rearrangement of allylic trichloroacetimidates. 1,3 Transposition of alcohol and amine functions . . 2901–2910 . 10.1021/ja00426a038 . . 10 . 1976 . 98.
2. Overman . L. E. . Allylic and propargylic imidic esters in organic synthesis . . 1980 . 13 . 7 . 218–224 . 10.1021/ar50151a005.
3. [Organic Syntheses]
4. Overman . L. E. . Thermal and mercuric ion catalyzed [3,3]-sigmatropic rearrangement of allylic trichloroacetimidates. 1,3 Transposition of alcohol and amine functions . . 1974 . 96 . 2 . 597–599 . 10.1021/ja00809a054.
5. Overman . L. E. . Carpenter . N. E. . 2005 . The Allylic Trihaloacetimidate Rearrangement. . 66 . 1 . 10.1002/0471264180.or066.01 . 0471264180 .
6. Chen . Y. K. . Lurain, A. E. . Walsh, P. J. . A General, Highly Enantioselective Method for the Synthesis of D and L α-Amino Acids and Allylic Amines . . 2002 . 124 . 41 . 12225–12231 . 10.1021/ja027271p . 12371863.
7. Anderson, C. E.; Overman, L. E. J. Am. Chem. Soc. 2003, 125, 12412–12413.
8. Asymmetric Overman Rearrangement Organic Syntheses, Vol. 82, p.134 (2005). (Article)