Robust and catalytically active mono- and bis-Pd-complexes of the ‘Trost modular ligand’

(Note: The full text of this document is currently only available in the PDF Version )

Craig P. Butts, John Crosby, Guy C. Lloyd-Jones and Susanna C. Stephen


Abstract

A catalytically active, bimetallic Pd–allyl complex of the Trost modular ligand, for which X-ray crystallography reveals a tetradentate (‘POPO’) coordination mode, induces a memory effect in Pd-catalysed allylic alkylation.


References

  1. G. Consiglio and R. M. Waymouth, Chem. Rev., 1989, 89, 257 CrossRef CAS; C. G. Frost, J. Howarth and J. M. J. Williams, Tetrahedron: Asymmetry, 1992, 3, 1089 CrossRef CAS; B. M. Trost and D. L. Van Vranken, Chem. Rev., 1996, 96, 395 CrossRef CAS.
  2. B. M. Trost, Acc. Chem. Res., 1996, 29, 355 CrossRef CAS.
  3. For examples of other ligands that effect high ee in this substrate class see: G. Helmchen, S. Kudis, P. Sennhenn and H. Steinhagen, Pure Appl. Chem., 1997, 69, 513 Search PubMed; P. Dierkes, S. Ramdeehul, L. Barloy, A. De Cian, J. Fischer, P. C. J. Kamer, P. W. N. M. van Leeuwen and J. A. Osborn, Angew. Chem. Int. Ed., 1998, 37, 3116 CrossRef CAS; A. Saitoh, M. Misawa and T. Morimoto, Tetrahedron: Asymmetry, 1999, 10, 1025 CrossRef CAS.
  4. B. M. Trost, B. Breit and M. G. Organ, Tetrahedron Lett., 1994, 35, 5817 CrossRef CAS.
  5. For leading references and the current working model, see: B. M. Trost and F. D. Toste, J. Am. Chem. Soc., 1999, 121, 4545 Search PubMed.
  6. (a) G. C. Lloyd-Jones and S. C. Stephen, Chem. Eur. J., 1998, 4, 2539 CrossRef CAS; (b) G. C. Lloyd-Jones and S. C. Stephen, Chem. Commun., 1998, 2321 RSC; (c) P. Kočovský, Š. Vyskočil, I. Císařová, J. Srjbal, I. Tišlerová, M. Smrčiná, G. C. Lloyd-Jones, S. C. Stephen, C. P. Butts, M. Murray and V. Langer, J. Am. Chem. Soc., 1999, in press Search PubMed.
  7. (a) B. M. Trost and R. C. Bunt, J. Am. Chem. Soc., 1996, 118, 235 CrossRef CAS; (b) J.-C. Fiaud and J. L. Malleron, Tetrahedron Lett., 1981, 22, 1399 CrossRef CAS; (c) T. Hayashi, M. Kawatsura and Y. Uozumi, J. Am. Chem. Soc., 1998, 120, 1681 CrossRef CAS.
  8. See ref. 5 and B. M. Trost and D. E. Patterson, J. Org. Chem., 1998, 63, 1339 Search PubMed.
  9. Prior to (and after) addition of [NaCH(CO2Me)2] the 31P NMR spectrum indicated the presence of many complexes whose relative abundance were time-dependent. A much more complete and detailed report of our NMR, kinetic and other studies on this complex mixture will be published in due course.
Click here to see how this site uses Cookies. View our privacy policy here.