Unexpected enhancement of enantioselectivity in copper(II) catalyzed conjugate addition of diethylzinc to cyclic enones with novel TADDOL phosphorus amidite ligands

Tetrahedron Asymmetry

Volumn 9, Issue 14, 1998, Pages 2409-2413

  Keller, Erik ^a   Maurer, Jochen ^a   Naasz, Robert ^a   Schader, Thomas ^b   Meetsma, Auke ^a   Feringa, Ben L ^a  

^a UNIVERSITY OF GRONINGEN   (Netherlands)

^b HEINRICH HEINE UNIVERSITY   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

ALPHA,ALPHA,ALPHA',ALPHA' TETRAPHENYL 2,2' DIMETHYL 1,3 DIOXOLANE 4,5 DIMETHANOL; COPPER DERIVATIVE; METHANOL DERIVATIVE; UNCLASSIFIED DRUG;

ARTICLE; CATALYSIS; CHIRALITY; CONJUGATE; DRUG SYNTHESIS; ENANTIOMER; LIGAND BINDING; OLIGOMERIZATION; PRIORITY JOURNAL; TANDEM REPEAT;

EID: 0032540965     PISSN: 09574166     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0957-4166(98)00240-7     Document Type: Article

References (29)

1. 1. Perlmutter, P. Conjugate Addition Reactions in Organic Synthesis, Tetrahedron Organic Chemistry Series, No. 9, Pergamon: Oxford, 1992.
2. 2. Zhou, Q.-L., Pfaltz, A. Tetrahedron 1994, 50, 4467.
3. 3. Van Klaveren, M., Lambert, R, Eijkelkamp, D. F. J. M., Grove, D. M., van Koten, G. Tetrahedron Lett. 1994, 35, 6135.
4. 4. Spescha, M., Rihs, G. Helv. Chim. Acta 1993, 76, 1219.
5. 5. Kanai, M., Tomioka, K. Tetrahedron Lett. 1995, 36, 4275.
6. 6. Seebach, D., Jeasche, G., Pichota, A., Audergon, L. Helv. Chim. Acta 1997, 80, 2515.
7. 7. de Vries, A. H. M., Hof, R. P., Staal, D., Kellogg, R. M., Feringa, B. L. Tetrahedron: Asymmetry 1997, 8, 1539.
8. 8. Soai, K., Hayasha, T., Ugajun, S., Yokoyama, S. Chem. Lett. 1988, 1571.
9. 9. Bolm, C., Ewald, M. Tetrahedron Lett. 1990, 31, 5011.
10. 10. de Vries, A. H. M., Jansen, J. F. G. A., Feringa, B. L. Tetrahedron 1994, 50, 4479.
11. 11. de Vries, A. H. M., Imbos, R., Feringa, B. L. Tetrahedron: Asymmetry 1997, 8, 1467.
12. 12. de Vries, A. H. M., Feringa, B. L. Tetrahedron: Asymmetry 1997, 8, 1377.
13. 13. For a review see: Feringa, B. L., de Vries, A. H. M. In Advances in Catalytic Processes, Doyle, M. P., Ed.; JAI Press Inc., 1995; Vol. 1, p. 151.
14. 14. Alexakis, A., Frutos, J., Mangeney, P. Tetrahedron: Asymmetry 1993, 4, 2427.
15. 15. de Vries, A. H. M., Meetsma, A., Feringa, B. L. Angew. Chem. Int. Ed. Engl. 1996, 35, 2374.
16. 16. Feringa, B. L., Pineschi, M., Arnold, L. A., Imbos, R., de Vries, A. H. M. Angew. Chem. Int. Ed. Engl. 1997, 36, 2620.
17. 17. Knöbel, A. K. N., Escher, H., Pfaltz, A. Synlett 1997, 1429.
18. 18. Alexakis, A., Burton, J., Vastra, J., Mangeney, P. Tetrahedron: Asymmetry 1997, 8, 3987; and references therein.
19. 19. Dahinden, R., Beck, A. K., Seebach, D. In Encyclopedia of Reagents for Organic Synthesis, John Wiley & Sons: Chichester, 1995; Vol. 3, p. 2167.
20. 20. Narasaka, K. Synthesis 1991, 1.
21. r=23.6 (R)/24.8 (S).
22. 22. Much to our surprise, addition of a small amount of water to the reaction mixture of the addition of diethyl zinc to cyclopentenone also increased the enantioselectivity, Keller, E., Imbos, R., Feringa, B. L. unpublished results.
23. 23. Posner, G. H., Dai, H., Bull, D. S., Lee, J., Eydoux, F., Ishihara, Y., Welsh, W., Pryor, N., Petr, S. J. Org. Chem. 1996, 61, 671.
24. 24. Oligomerization of the intermediate zinc enolate is generally observed, see also Ref. 25.
25. 25. Kitamura, M., Miki, T., Nakano, K., Noyori, R. Tetrahedron Lett. 1996, 37, 5141.
26. 26. Noyori, R. Asymmetric Catalysis in Organic Synthesis, John Wiley & Sons: New York, 1994; p. 298.
27. r=21.7 (S,S).
28. 2 hexanes:diethylether) or crystallization. All spectroscopic and analytical data are in accordance with the proposed structures.
29. o) criterion of observability. Atomic coordinates, thermal parameters, bond lengths and angles have been deposited at the Cambridge Crystallographic Data Centre.