Double diastereodifferentiation in the Mukaiyama aldol reactions of π-allyltricarbonyliron lactone complexes: 1,7- vs. 1,2-asymmetric induction

Abstract

The Mukaiyama aldol reactions of trimethylsilyl enol ether-substituted π-allyltricarbonyliron lactone complexes with chiral aldehydes under BF₃·OEt₂ activation proceed with high levels of substrate control (1,7-induction), overriding possible 1,2-induction from the aldehyde stereogenic centre. When TiCl₄ is used as the Lewis acid with (R )- or (S )-2-benzyloxypropanal, however, chelation control (1,2-induction) is observed, overriding the templating effect of the iron complex.

References

1. For recent reviews on stereoselectivity in the aldol reaction see: (a) A. S. Franklin and I. Paterson, Contemp. Org. Synth., 1994, 1, 317; (b) S. G. Nelson, Tetrahedron: Asymmetry, 1998, 9, 357.
2. (a) D. J. Cram and D. R. Wilson, J. Am. Chem. Soc., 1963, 85, 1245; (b) M. T. Reetz, K. Kessler and A. Jung, Tetrahedron, 1984, 40, 4327.
3. (a) For a discussion of 1,2- and 1,3-asymmetric induction in Mukaiyama aldol reactions of chiral aldehydes see: D. A. Evans, M. J. Dart, J. L. Duffy and M. G. Yang, J. Am. Chem. Soc., 1996, 118, 4322; (b) for a recent discussion of the Felkin-Anh and Cram chelation models see: R. E. Gawley and J. Aubé, 1,2 and 1,4 Additions to Carbonyls, in Principles of Asymmetric Synthesis, Tetrahedron Organic Chemistry Series, ed. J. E. Baldwin and P. D. Magnus, Pergamon Press, Oxford, 1996, pp. 121–160.
4. (a) M. Chérest, H. Felkin and N. Prudent, Tetrahedron Lett., 1968, 2199; M. Chérest and H. Felkin, Tetrahedron Lett., 1968, 2205; (b) N. T. Anh and O. Eisenstein, Nouv. J. Chem., 1977, 1, 61.
5. S. Masamune, W. Choy, J. S. Peterson and L. R. Sita, Angew. Chem., Int. Ed. Engl., 1985, 24, 1.
6. M. Franck-Neumann, P.-J. Colson, P. Geoffroy and K. M. Taba, Tetrahedron Lett., 1992, 33, 1903.
7. M. Franck-Neumann, P. Bissinger and P. Geoffroy, Tetrahedron Lett., 1997, 38, 4469; Tetrahedron Lett., 1997, 38, 4477.
8. M. Franck-Neumann, P. Bissinger and P. Geoffroy, Tetrahedron Lett., 1997, 38, 4473.
9. S. V. Ley and L. R. Cox, Chem. Commun., 1998, 227.
10. S. V. Ley, L. R. Cox, B. Middleton and J. M. Worrall, Chem. Commun., 1998, 1339.
11. S. V. Ley and L. R. Cox, J. Chem. Soc., Perkin Trans. 1, 1997, 3315.
12. S. V. Ley, L. R. Cox, B. Middleton and J. M. Worrall, Tetrahedron, in press.
13. S. Kiyooka and C. H. Heathcock, Tetrahedron Lett., 1983, 24, 4765.
14. C. H. Heathcock and L. A. Flippin, J. Am. Chem. Soc., 1983, 105, 1667.
15. S. V. Ley, L. R. Cox, G. Meek, K.-H. Metten, C. Piqué and J. M. Worrall, J. Chem. Soc., Perkin Trans. 1, 1997, 3299.
16. D. A. Evans, D. L. Reiger and J. R. Cage, Tetrahedron Lett., 1990, 31, 7099.
17. S. D. Rychnovsky and D. J. Skalitzky, Tetrahedron Lett., 1990, 31, 945.
18. S. D. Rychnovsky, B. Rogers and G. Yang, J. Org. Chem., 1993, 58, 3511.
19. M. T. Reetz, M. Hüllmann, W. Massa, S. Berger, P. Rademacher and P. Heymanns, J. Am. Chem. Soc., 1986, 108, 2405.
20. (a) S. Masamune, S. A. Ali, D. L. Snitman and D. S. Garvey, Angew. Chem., Int. Ed. Engl., 1980, 19, 557; (b) D. A. Evans and J. Bartroli, Tetrahedron Lett., 1982, 23, 807.
21. S. V. Ley, L. R. Cox and G. Meek, Chem. Rev., 1996, 96, 423 and references cited therein.
22. S. V. Ley, S. Burckhardt, L. R. Cox and J. M. Worrall, Chem. Commun., 1998, 229.
23. D. D. Perrin and W. L. F. Armarego, Purification of Laboratory Chemicals, Pergamon Press, Oxford, 1988.