Enantioselective palladium-catalyzed allylic alkylation using E- and Z-vinylogous sulfonates

Organic Letters

Volumn 1, Issue 10, 1999, Pages 1563-1565

  Evans, Andrew P ^a   Brandt, Thomas A ^a  

^a UNIVERSITY OF DELAWARE   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0001218599     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol990879r     Document Type: Article

References (26)

1. Tsuji, J. In Palladium Reagents and Catalysts; Wiley: New York, 1996; Chapter 4, pp 290-404.
2. For some recent reviews on the Pd(0)-catalyzed allylic alkylation, see: (a) Frost, C. G.; Howarth, J.; Williams, J. M. J. Tetrahedron: Asymmetry 1992, 3, 1089.
3. (b) Hayashi, T. In Catalytic Asymmetric Synthesis; Ojima, I. Ed; VCH Publishers; New York, 1993; p 325.
4. (c) Trost, B. M.; Van Vranken, D. L. Chem. Rev. 1996, 96, 395.
5. For some of the early conceptual contributions to Pd(0)-catalyzed allylic alkylation, see: (a) Hayashi, T.; Yamamoto, A.; Hagihara, T.; Ito, Y. Tetrahedron Lett. 1986, 27, 191.
6. (b) Trost, B. M.; Van Vranken, D. L. Angew. Chem., Int. Ed. Engl. 1992, 31, 228.
7. (c) von Matt, P.; Pfaltz, A. Angew. Chem., Int. Ed. Engl. 1993, 32, 566.
8. (d) Sprinz, J.; Helmchen, G. Tetrahedron Lett. 1993, 34, 1769.
9. (e) Dawson, G. J.; Frost, C. G.; Williams, J. M. J.; Coote, S. J. Tetrahedron Lett. 1993, 34, 3149. For a more recent Mo-catalyzed allylic alkylation procedure using aryl derivatives, see: Trost, B. M.; Hachiya, I. J. Am. Chem. Soc. 1998, 120, 1104.
10. (e) Dawson, G. J.; Frost, C. G.; Williams, J. M. J.; Coote, S. J. Tetrahedron Lett. 1993, 34, 3149. For a more recent Mo-catalyzed allylic alkylation procedure using aryl derivatives, see: Trost, B. M.; Hachiya, I. J. Am. Chem. Soc. 1998, 120, 1104.
11. For an exhaustive citation of the literature pertaining to the asymmetric Pd(0)-catalyzed allylic alkylation reactions, see: Vyskocil, S.; Jaracz, S.; Smrcina, M.; Stícha, M.; Hanus, V.; Polásek, M.; Kocovsky, P. J. Org. Chem. 1998, 63, 7727. For recent eamples, see: (a) Evans, D. A.; Campos, K. R.; Tedrow, J. S.; Michael, F. E.; Gagné, M. R. J. Org. Chem. 1999, 64, 2994.
12. For an exhaustive citation of the literature pertaining to the asymmetric Pd(0)-catalyzed allylic alkylation reactions, see: Vyskocil, S.; Jaracz, S.; Smrcina, M.; Stícha, M.; Hanus, V.; Polásek, M.; Kocovsky, P. J. Org. Chem. 1998, 63, 7727. For recent eamples, see: (a) Evans, D. A.; Campos, K. R.; Tedrow, J. S.; Michael, F. E.; Gagné, M. R. J. Org. Chem. 1999, 64, 2994.
13. (b) Yonehara, K.; Hashizume, T.; Mori, K.; Ohe, S.; Uemura, S. J. Chem. Soc., Chem. Commun. 1999, 514.
14. (c) Saitoh, A.; Misawa, M.; Morimoto, T. J. Synlett 1999, 483.
15. Evans, P. A.; Brandt, T. A. Tetrahedron Lett. 1996, 37, 9143.
16. For examples of the enantioselective (≥90% ee) Pd(0)-catalyzed allylic alkylation of alkyl substituted allylic systems, see: (a) Dawson, G. J.; Williams, J. M. J.; Coote, S. J. Tetrahedron: Asymmetry 1995, 6, 2535.
17. (b) Trost, B. M.; Radinov, R. J. Am. Chem. Soc. 1997, 119, 5962.
18. (c) Glorius, F.; Pfaltz, A. Org. Lett. 1999, 1, 141.
19. Auburn, P. R.; MacKenzie, P. B.; Bosnich, B. J. Am. Chem. Soc. 1985, 107, 2033.
20. Preliminary studies demonstrated that the nature of the leaving group was crucial to the success of this transformation using the phosphino-1,3-oxazine ligand 3. Treatment of the allylic acetate 6a with the sodium salt of dimethyl malonate and the palladium catalyst derived from the phosphino-1,3-oxazine ligand 3, failed to give any of the desired product 4a under a variety of reaction conditions. matrix presented This observation prompted the examination of alternative leaving groups for this system. Treatment of the allylic carbonate 7a under similar conditions furnished the allylic alkylation product 4a in 55% yield, albeit with modest enantiomeric excess (82% ee). The trifluoroacetate derivative 8a proved less effective due to hydrolysis, furnishing the alcohol 5a (68%) and the allylic alkylation product 4a in only 28% yield with 85% ee.
21. Evans, P. A.; Brandt, T. A.; Robinson, J. E. Tetrahedron Lett. 1999, 40, 3105.
22. For a leading reference on the effect of the metal counterion on enantioselectivity and turnover rate, see: Burckhardt, U.; Baumann, M.; Togni, A. Tetrahedron: Asymmetry 1997, 8, 155 and pertinent references therein.
23. For the stereospecific synthesis of E- and Z-vinylogous sulfonates, see: Meek, J. S.; Fowler, J. S. J. Org. Chem. 1968, 33, 985.
24. 6a The vinylogous sulfonates of β-phenyl-cinnamyl alcohols with aryl substituents are however particularly unstable due to ionization of the leaving group.
25. Spritz, J.; Kiefer, M.; Helmchen, G.; Reggelin, M.; Huttner, G.; Walter, O.; Zsolnai, L. Tetrahedron Lett. 1994, 35, 1523 and pertinent references therein.
26. For the first example of a microwave-catalyzed asymmetric palladium-catalyzed allylic alkylation, see: Bremberg, U.; Larhed, M.; Moberg, C.; Hallberg, A. J. Org. Chem. 1999, 64, 1082.