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DOI: 10.1039/A704091A (Paper) Reference Section for: J. Chem. Soc., Dalton Trans., 1997, 3421-3425

Structural studies of lithiated enaminones: the 1-oxa-5-azapentadienyllithium fluxional heterocubane [(PriN[upper bond 1 start]CMeCHCMeOL[upper bond 1 end]i)4] and its dimeric hexamethylphosphoric triamide complex [{PriN[upper bond 1 start]CMeCHCMeOL[upper bond 1 end]i·OP(NMe2)3}2]

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Margaret Brehon, Elaine K. Cope, Francis S. Mair, Philip Nolan, John E. O’Brien, Robin G. Pritchard and Deborah J. Wilcock

Abstract

Lithiation of 4-isopropylaminopent-3-en-2-one in hexane gave a 1-oxa-5-azapentadienyl compound [(PriN[upper bond 1 start]CMeCHCMeOL[upper bond 1 end]i)4] 1, which comprises a tetrameric aggregate of Li4 and O4 interpenetrating tetrahedra in which chelating terminal nitrogens undergo a fluxional process around each face of the Li4 tetrahedron in toluene solution. Addition of hexamethylphosphoric triamide (hmpa) produced a dimeric complex 2 in which oxygen bridges are retained. The crystal structures of both compounds were determined. Bond lengths indicate that an iminoenolate form of the ligand predominates, irrespective of aggregation state. The data are used to rationalise the selectivity of dimetallations of enaminones.

References

  1. D. Stalke, Angew. Chem., Int. Ed. Engl., 1994, 33, 2136 CrossRef.
  2. A. Togni and L. M. Venanzi, Angew. Chem., Int. Ed. Engl., 1994, 33, 497 CrossRef.
  3. D. L. Schulz, B. J. Hinds, D. A. Neumayer, C. L. Stern and T. J. Marks, Chem. Mater., 1993, 1605 CrossRef CAS.
  4. F. S. Mair, D. Scully, A. J. Edwards, P. R. Raithby and R. Snaith, Polyhedron, 1995, 14, 2397 CrossRef CAS.
  5. M. Fieser, Reagents for Organic Synthesis, Wiley-Interscience, New York, 1990, vol. 15 Search PubMed.
  6. (a) G. Bartoli, M. Bosco, C. Cimarelli, R. Dalpozzo and G. Palmieri, Synlett, 1991, 229 CrossRef CAS; (b) J. Chem. Soc., Perkin Trans 1, 1992, 2095 Search PubMed; (c) G. Bartoli, M. Bosco, C. Cimarelli, R. Dalpozzo, G. Guercio and G. Palmieri, J. Chem. Soc., Perkin Trans 1, 1993, 2081 RSC; (d) G. Bartoli, M. Bosco, C. Cimarelli, R. Dalpozzo, M. Guerra and G. Palmieri, J. Chem. Soc., Perkin Trans. 2, 1992, 649 RSC; (e) G. Bartoli, E. Marcantoni, M. Petrini and L. Sambri, Chem. Eur. J., 1996, 2, 913 CrossRef CAS; (f) G. Bartoli, M. Bosco, C. Cimarelli, R. Dalpozzo, G. De Munno, G. Guercio and G. Palmieri, J. Org. Chem., 1992, 57, 6020 CrossRef CAS; (g) G. Bartoli, M. Bosco, C. Cimarelli, R. Dalpozzo and G. Palmieri, Tetrahedron, 1993, 49, 2521 CrossRef CAS; (h) G. Bartoli, M. Bosco, C. Cimarelli and G. Rafiani, Tetrahedron: Asymm., 1992, 3, 719 CrossRef CAS; (i) G. Bartoli, M. Bosco, C. Cimarelli, R. Dalpozzo, G. De Munno and G. Palmieri, Tetrahedron: Asymm., 1993, 4, 1651 CrossRef CAS.
  7. R. V. Singh and J. P. Tandon, J. Prakt. Chem., 1979, 321, 151 CrossRef CAS.
  8. G. M. Sheldrick, Acta Crystallogr., Sect. A, 1990, 46, 467 CrossRef.
  9. G. M. Sheldrick, SHELXL 93, University of Göttingen, 1993.
  10. T. Maetzke, C. P. Hidber and D. Seebach, J. Am. Chem. Soc., 1990, 112, 8248 CrossRef CAS.
  11. T. Maetzke and D. Seebach, Organometallics, 1990, 9, 3032 CrossRef CAS.
  12. R. E. Mulvey, Chem. Soc. Rev., 1991, 20, 167 RSC.
  13. P. A. van der Schaaf, J. T. B. H. Jastrzebski, M. P. Hogerheide, W. J. J. Smeets, A. L. Spek, J. Boersma and G. van Koten, Inorg. Chem., 1993, 32, 4111 CrossRef CAS.
  14. P. G. Williard and J. M. Salvino, Tetrahedron Lett., 1985, 26, 3913 CrossRef.
  15. J. T. B. H. Jastrzebski, G. van Koten, M. J. N. Christophersen and C. H. Stam, J. Organomet. Chem., 1985, 292, 319 CrossRef CAS.
  16. G. W. Klumpp, M. Vos, F. J. J. De Kanter, C. Slob, H. Krabbendam and A. L. Spek, J. Am. Chem. Soc., 1985, 107, 99; K. S. Lee, P. G. Williard and J. W. Suggs, J. Organomet. Chem., 1986, 299, 311 CrossRef CAS.
  17. D. R. Armstrong, S. Bennet, M. G. Davidson, R. Snaith, D. Stalke and D. S. Wright, J. Chem. Soc., Chem. Commun., 1992, 262 RSC.
  18. K. Gregory, P. von R. Schleyer and R. Snaith, Adv. Inorg. Chem., 1991, 37, 47 CrossRef CAS.
  19. M. G. Davidson and R. Snaith, personal communication.
  20. W. Clegg, M. MacGregor, R. E. Mulvey and P. A. O'Neil, Angew. Chem., Int. Ed. Engl., 1992, 31, 93 CrossRef.
  21. H. K. Shin, M. J. Hampden-Smith, T. T. Kodas and A. L. Rheingold, J. Chem. Soc., Chem. Commun., 1992, 217 RSC.
  22. D. Kost, E. H. Carlson and M. Raban, Chem. Commun., 1971, 656 RSC.
  23. R. D. Thoms, M. T. Clarke, R. M. Jensen and T. C. Young, Organometallics, 1986, 5, 1851 CrossRef CAS.
  24. W. Bauer and C. Griesinger, J. Am. Chem. Soc., 1993, 115, 1087.
  25. D. Seebach, Angew. Chem., Int. Ed. Engl., 1988, 27, 1624 CrossRef.
  26. (a) F. E. Romesberg, J. H. Gilchrist, A. T. Harrison, D. J. Fuller and D. B. Collum, J. Am. Chem. Soc., 1991, 113, 5751 CrossRef CAS; (b) Q.-Y. Liu and P. G. Williard, J. Am. Chem. Soc., 1993, 115, 3380 CrossRef CAS.
  27. W. Clegg, L. Horseburgh, R. E. Mulvey and M. J. Ross, Angew. Chem., Int. Ed. Engl., 1995, 34, 1233 CrossRef CAS.
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