Copper-catalyzed enantioselective conjugate addition of diethylzinc to acyclic enones in the presence of planar-chiral phosphaferrocene-oxazoline ligands

Organic Letters

Volumn 4, Issue 21, 2002, Pages 3699-3702

  Shintani, Ryo ^a   Fu, Gregory C ^a  

^a MASSACHUSETTS INSTITUTE OF TECHNOLOGY   (United States)

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ARTICLE;

EID: 0001074732     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol026651c     Document Type: Article

References (20)

1. Perlmutter, P. Conjugate Addition Reactions in Organic Synthesis; Tetrahedron Organic Chemistry Series Volume 9; Pergamon: Tarrytown, NY, 1992.
2. For an overview, see: (a) Tomioka, K.; Nagaoka, Y. In Comprehensive Asymmetric Catalysis; Jacobsen, E. N., Pfaltz, A., Yamamoto, H., Eds.; Springer-Verlag: New York, 1999; Chapter 31.1. Feringa, B. L.; Naasz, R.; Imbos, R.; Arnold, L. A. In Modern Organocopper Chemistry; Krause, N., Ed.; Wiley-VCH: New York, 2002, Chapter 7.
3. For an overview, see: (a) Tomioka, K.; Nagaoka, Y. In Comprehensive Asymmetric Catalysis; Jacobsen, E. N., Pfaltz, A., Yamamoto, H., Eds.; Springer-Verlag: New York, 1999; Chapter 31.1. Feringa, B. L.; Naasz, R.; Imbos, R.; Arnold, L. A. In Modern Organocopper Chemistry; Krause, N., Ed.; Wiley-VCH: New York, 2002, Chapter 7.
4. (b) Yamaguchi, M. In Comprehensive Asymmetric Catalysis; Jacobsen, E. N., Pfaltz, A., Yamamoto, H., Eds.; Springer-Verlag: New York, 1999; Chapter 31.2.
5. (c) Krause, N.; Hoffmann-Roder, A. Synthesis 2001, 171-196.
6. For recent progress and leading references, see: (a) Alexakis, A.; Benhaim, C.; Rosset, S.; Humam, M. J. Am. Chem. Soc. 2002, 124, 5262-5263.
7. (b) Mizutani, H.; Degrade, S. J.; Hoveyda, A. H. J. Am. Chem. Soc. 2002, 124, 779-780.
8. (c) Feringa, B. L. Acc. Chem. Res. 2000, 33, 346-353.
9. (d) Hu, X.; Chen, H.; Zhang, X. Angew. Chem., Int. Ed. 1999, 38, 3518-3521.
10. Shintani, R.; Lo, M. M.-C; Fu, G. C. Org. Lett. 2000, 2, 3695-3697.
11. For applications in asymmetric catalysis of chiral phosphaferrocenes that do not bear an oxazoline, see: (a) Qiao, S.; Fu, G. C. J. Org. Chem. 1998, 63, 4168-4169.
12. (b) Ganter, C.; Kaulen, C.; Englert, U. Organometallics 1999, 18, 5444-5446. See also: Ganter, C.; Glinsböckel, C.; Ganter, B. Eur. J. Inorg. Chem. 1998, 1163-1168.
13. (b) Ganter, C.; Kaulen, C.; Englert, U. Organometallics 1999, 18, 5444-5446. See also: Ganter, C.; Glinsböckel, C.; Ganter, B. Eur. J. Inorg. Chem. 1998, 1163-1168.
14. (c) Tanaka, K.; Qiao, S.; Tobisu, M.; Lo, M. M.-C.; Fu, G. C. J. Am. Chem. Soc. 2000, 122, 9870-9871. Tanaka, K.; Fu, G. C. J. Org. Chem. 2001, 66, 8177-8186.
15. (c) Tanaka, K.; Qiao, S.; Tobisu, M.; Lo, M. M.-C.; Fu, G. C. J. Am. Chem. Soc. 2000, 122, 9870-9871. Tanaka, K.; Fu, G. C. J. Org. Chem. 2001, 66, 8177-8186.
16. (d) Ogasawara, M.; Yoshida, K.; Hayashi, T. Organometallics 2001, 20, 3913-3917.
17. Holand, S.; Jeanjean, M.; Mathey, F. Angew. Chem., Int. Ed. Engl. 1997, 36, 98-100.
18. The structures of 7a′, 7b, and 7c′ were determined by X-ray crystallography (see Supporting Information for the structure of 7a′).
19. 2 to 2-cyclohexen-1-one in 78% ee and 83% yield.
20. Under identical conditions, Cu(OTf)/7c catalyzes the conjugate addition of ZnMez to chalcone in 89% ee in a very slow process (<10% conversion after 18 h at 0 °C). (11) For a review of nonlinear effects in asymmetric catalysis, see: Kagan, H. B.; Luukas, T. O. In Comprehensive Asymmetric Catalysis; Jacobsen, E. N., Pfaltz, A., Yamamoto, H., Eds.; Springer: New York, 1999; Chapter 4.1.