Chiral arene ruthenium complexes as asymmetric Diels–Alder catalysts

Abstract

The cation [RuCl(L)(η⁶-mes)]⁺ [L = 4-isopropyl-2-(2-pyridyl)-1,3-oxazoline] is synthesised diastereoselectively; treatment with AgSbF₆ gives a dication which is an enantioselective catalyst for the asymmetric Diels–Alder reaction between methacrolein and cyclopentadiene.

References

1. Catalytic Asymmetric Synthesis, ed. I. Ojima, VCH, Weinheim, 1993; R. Noyori, Asymmetric Catalysis in Organic Synthesis, Wiley, New York, 1994.
2. H. B. Kagan and O. Riant, Chem. Rev., 1992, 92, 1007; K. Narasaka, Synthesis, 1991, 1.
3. (a) S. Kobayashi and H. Ishitani, J. Am. Chem. Soc., 1994, 116, 4083; (b) D. A. Evans, J. A. Murry, P. von Matt, R. D. Norcross and S. J. Miller, Angew. Chem., Int. Ed. Engl., 1995, 34, 798; (c) D. A. Evans, S. J. Miller and T. Lectka, J. Am. Chem. Soc., 1993, 115, 6460; (d) J. Jaquith, J. Guan, S. Wang and S. Collins, Organometallics, 1995, 14, 1079; (e) S. Kobayashi, H. Ishitani, I. Hachiya and M. Araki, Tetrahedron, 1994, 50, 11623; (f) E. J. Corey, N. Imai and H.-Y. Zhang, J. Am. Chem. Soc., 1991, 113, 728.
4. D. Carmona, C. Cativiela, R. Garcia-Correas, F. J. Lahoz, M. P. Lamata, J. A. Lopez, M. P. Lopez-Ram de Viu, L. A. Oro, E. San Jose and F. Viguri, Chem. Commun., 1996, 1247; E. P. Kundig, B. Bourdin and G. Bernardinelli, Angew. Chem., Int. Ed. Engl., 1994, 33, 1856.
5. (a) A. Pfaltz, Acc. Chem. Res., 1993, 26, 339; (b) D. A. Evans, K. A. Woerpel, M. M. Hinman and M. M. Faul, J. Am. Chem. Soc., 1991, 113, 726; (c) A. Pfaltz, Acta Chem. Scand., 1996, 50, 189.
6. G. J. Dawson, J. M. J. Williams and S. J. Coote, Tetrahedron. Lett., 1995, 36, 461 and references therein.
7. H. Asano, K. Katayama and H. Kurosawa, Inorg. Chem., 1996, 35, 5760.
8. (a) S. K. Mandal and A. R. Chakravarty, Polyhedron, 1992, 11, 823; (b) D. L. Davies, J. Fawcett, R. Krafczyk and D. R. Russell, submitted for publication.
9. T. E. Sloan, Top. Stereochem., 1981, 12, 1; K. Stanley and M. C. Baird, J. Am. Chem. Soc., 1975, 97, 6598.