Temperature and solvent effects in facial diastereoselectivity of nucleophilic addition: entropic and enthalpic contribution

Abstract

Solvent and temperature effects on facial diastereoselectivity of nucleophilic addition have been long observed but often neglected. Temperature dependent measurements according to the modified Eyring equation allow the evaluation of stereoselectivity in terms of differential enthalpy and entropy of activation, and demonstrate the paramount importance of entropic contribution in directing the facial diastereoselectivity. Even the reaction solvent proved to be important in determining the isomer ratio. In many cases Eyring plots show a non-linear behavior consisting of two linear regions intersecting at a point called the inversion temperature (T_inv) which, for the same reaction, depends on the nature of the solvent and correlates with their melting points. We propose that T_inv is the temperature value for the interconversion between two different solvation clusters which should behave like two different molecules.

References

1. R. E. Gawley and J. Aubè, in Principles of Asymmetric Synthesis, Tetrahedron Organic Chemistry Series, vol.14, ed. J. E. Baldwin, F. R. S. Magnus and P. D. Magnus, Pergamon Press, Oxford, 1996; D. J. Ager and M. B. East, in Asymmetric Synthetic Methodology, CRC Press, 1996.
2. M. T. Reetz, Angew. Chem., Int. Ed. Engl., 1984, 23, 556.
3. N. C. DeMello and D. P. Curran, J. Am. Chem. Soc., 1998, 120, 329.
4. E. L. Eliel, S. H. Wilen and L. N. Mander, in Stereochemistry of Organic Compounds, Wiley, New York, 1994, p. 875.
5. B. Giese, Acc. Chem. Res., 1984, 17, 438 and references cited therein R. E. Rosenberg and J. S. Vilardo, Tetrahedron Lett., 1996, 37, 2185.
6. See for instanc: N. Hoffmann, H. Buschmann, G. Raabe and H.-D. Scharf, Tetrahedron, 1994, 50, 11167; D. Awandi, F. Henin, J. Muzart and J.-P. Pete, Tetrahedron: Asymmetry, 1991, 2, 1101; C. Zioudrou and P. Chrysochou, Tetrahedron, 1977, 33, 2103.
7. Y. Inoue, N. Yamasaki, T. Yokoyama and A. Tai, J. Org. Chem., 1992, 57, 1332.
8. H. Buschmann, H.-D. Scharf, N. Hoffmann, M. W. Plath and J. Runsink, J. Am. Chem. Soc., 1989, 11, 5367; M. Palucki, P. J. Pospisil, W. Zhang and E. N. Jacobsen, J. Am. Chem. Soc., 1994, 116, 9333; J. Brunne, N. Hoffmann and H.-D. Scharf, Tetrahedron, 1994, 50, 6819; T. Göbel and K. B. Sharpless, Angew. Chem., 1993, 105, 1417; Angew. Chem., Int. Ed. Engl., 1993, 32, 1329; J. Muzart, F. Hénin, J.-P. Pète and A. M'boungou-M'Passi, Tetrahedron: Asymmetry, 1993, 4, 2531; I. Tóth, I. Guo and B. E. Hanson, Organometallics, 1993, 12, 477; I. E. Markò, A. Chesney and D. M. Hollinshead, Tetrahedron: Asymmetry, 1994, 5, 569.
9. H. Buschmann, H.-D. Scharf, N. Hoffmann and P. Esser, Angew. Chem., 1991, 103, 480; Angew. Chem., Int. Ed. Engl., 1991, 30, 477.
10. K. J. Hale and J. H. Ridd, J. Chem. Soc., Perkin Trans. 2, 1995, 1601; J. Hale and J. H. Ridd, J. Chem. Soc., Chem. Commun., 1995, 357.
11. C. Reichardt, in Solvents and Solvent Effects in Organic Chemistry, 2nd edn., VCH, Weinheim, 1990.
12. See for recent examples: M. T. Crimmins and A. L. Choy, J. Am. Chem. Soc., 1997, 119, 10237; R. W. Murray, M. Singh, B. L. Williams and H. M. Moncrieff, Tetrahedron Lett., 1995, 36, 2437; T. Saito, M. Kawamura and J. Nishimura, Tetrahedron Lett., 1997, 38, 8231; P. Wipf and J.-K. Jung, Angew. Chem., Int. Ed. Engl., 1997, 36, 764; S. E. Denmark, N. Nakajima and O. J.-C. Nicaise, J. Am. Chem. Soc., 1994, 116, 8797; M. T. Reetz, S. Stanchev and H. Haning, Tetrahedron, 1992, 48, 6813.
13. G. Cainelli, D. Giacomini and F. Perciaccante, Tetrahedron: Asym-metry, 1994, 5, 1913.
14. See for instance: Y.-T. Hsieh, G.-H. Lee, Y. Wang and T.-Y. Luh, J. Org. Chem., 1998, 63, 1484.
15. B. Lecea, A. Arrieta and F. P. Cossío, J. Org. Chem., 1997, 62, 6485; L. Perrin, M. A. Fabian and I. A. Rivero, J. Am. Chem. Soc., 1998, 120, 1044.
16. D. J. Giesen, C. J. Cramer and D. G. Truhlar, J. Phys. Chem., 1995, 99, 7137; G. D. Hawkins, D. A. Liotard, C. J. Cramer and D. G. Truhlar, J. Org. Chem., 1998, 63, 4305; M. F. Ruiz-Lopez, X. Assfeld, J. I. Garcia, J. A. Mayoral and L. Salvatella, J. Am. Chem. Soc., 1993, 115, 8780; M. Sola, A. Lledos, M. Duran, J. Bertran and J.-L. M. Abboud, J. Am. Chem. Soc., 1991, 113, 2873.
17. G. Cainelli, D. Giacomini and M. Walzl, Angew. Chem., 1995, 107, 2336; Angew. Chem., Int. Ed. Engl., 1995, 34, 2150.
18. M. Schlosser, in Organometallics in Synthesis, Wiley, New York, 1994, p. 11.
19. Preliminary experiments using different organometallic reagents with almost certainly different aggregations, such as Bu^tLi and BuⁿMgBr, show for the same carbonyl compound the same T_inv.
20. G. Cainelli, D. Giacomini, P. Galletti and A. Marini, Angew. Chem., Int. Ed. Engl., 1996, 35, 2849.
21. G. Cainelli, D. Giacomini and P. Galletti, unpublished results.
22. J. Muzart, F. Hénin and S. J. Aboulhoda, Tetrahedron: Asymmetry, 1997, 8, 381.
23. M. S. Searle and D. H. Williams, J. Am. Chem. Soc., 1992, 114, 10690.
24. The possibility of partial ordering of molecules in solution exists and a temperature dependent change in this order is already manifested in a non-linear behaviour of some spectroscopic properties. See, J. B. Robert, Mol. Phys., 1997, 90, 399; M. A. Wendt, J. Meiler, F. Weinhold and T. C. Farrar, Mol. Phys., 1998, 93, 145.
25. H. Pracejus and A. Tille, Chem. Ber., 1963, 854.