Palladium-catalysed Cyclisation and Cyclisation–Carbonylation of Unsaturated C-Glycoside Derivatives. The Importance of Relative Stereochemistry

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Cedric W. Holzapfel and Lizel Marais


Abstract

The Pd-catalysed `metallo-ene type' cyclisation and cyclisation–carbonylation of selected 2,3-unsaturated C-glycosides is described and attention is drawn to the importance of relative stereochemistry in the latter type of reactions.


References

  1. Reviews: (a) W. Oppolzer, Pure Appl. Chem., 1990, 62, 1941 CAS ; (b) W. Oppolzer, Angew. Chem., Int. Ed. Engl., 1989, 28, 38 CrossRef ; (c) W. Oppolzer, In Comprehensive Organic Synthesis, ed. B. M. Trost and I. Fleming, Pergamon Press, Oxford, 1991, vol. 5, p. 29 Search PubMed .
  2. Further examples include: (a) J.-F. Nguefack, V. Bolitt and D. Sinou, J. Org. Chem., 1997, 62, 1341 CrossRef CAS ; (b) J.-F. Nguefack, V. Bolitt and D. Sinou, Tetrahedron Lett., 1996, 37, 59 CrossRef CAS .
  3. C. W. Holzapfel, G. J. Engelbrecht, L. Marais and F. Toerien, Tetrahedron, 1997, 53, 3957 CrossRef CAS .
  4. Preliminary results on a part of this work: G. J. Engelbrecht and C. W. Holzapfel, Tetrahedron Lett., 1991, 32, 2161 Search PubMed .
  5. The acetic acid is thought to promote the reaction by protonation of the acetate ligand, thereby facilitating the formation of a cationic (η3-allyl)palladium complex, a key intermediate in these reactions: E. Gómez-Bengoa, J. M. Cuerva, A. M. Echavarren and G. Martorell, Angew. Chem., Int. Ed. Engl., 1997, 36, 767 Search PubMed .
  6. (a) W. Oppolzer and J.-M. Gaudin, Helv. Chim. Acta, 1987, 70, 1477 CAS ; (b) W. Oppolzer, Pure Appl. Chem., 1988, 60, 39 CAS .
  7. L. S. Hegedus, Transition Metals in the Synthesis of Complex Organic Molecules, University Science Books, Mill Valley, USA, 1994, 23 Search PubMed .
  8. This observation has been previously made, see: W. Oppolzer and J. Ruiz-Montes, Helv. Chim. Acta, 1993, 76, 1266 Search PubMed .
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