Catalytic and enantioselective route to medium-ring heterocycles. Asymmetric zirconium-catalyzed ethylmagnesation of seven- and eight-membered rings

Journal of the American Chemical Society

Volumn 118, Issue 18, 1996, Pages 4291-4298

  Visser, Michael S ^a   Heron, Nicola M ^a   Didiuk, Mary T ^a   Sagal, John F ^a   Hoveyda, Amir H ^a  

^a BOSTON COLLEGE   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

HETEROCYCLIC COMPOUND;

ARTICLE; CATALYSIS; ENANTIOMER; REACTION TIME; STEREOCHEMISTRY; STEREOSPECIFICITY;

EID: 17544377767     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja960163g     Document Type: Article

References (18)

1. (a) Morken, J. P.; Didiuk, M. T.; Hoveyda, A. H. J. Am. Chem. Soc. 1993, 115, 6697-6698.
2. (b) Didiuk, M. T.; Johannes, C. W.; Morken, J. P.; Hoveyda, A. H. J. Am. Chem. Soc. 1995, 117, 7097-7104 and references cited therein.
3. Visser, M. S.; Hoveyda, A. H. Tetrahedron 1995, 51, 4383-4394.
4. Morken, J. P.; Didiuk, M. T.; Visser, M. S.; Hoveyda, A. H. J. Am. Chem. Soc. 1994, 116, 3123-3124.
5. Visser, M. S.; Harrity, J. P. A.; Hoveyda, A. H. J. Am. Chem. Soc., in press.
6. (a) Fu, G. C.; Nguyen, S. Y.; Grubbs, R. H. J. Am. Chem. Soc. 1993, 115, 9856-9857 and references cited therein.
7. (b) Fujimura, O.; Fu, G. C.; Grubbs, R. H. J. Org. Chem. 1994, 59, 4029-4030.
8. (c) Kim, S. H.; Bowden, N.; Grubbs, R. H. J. Am. Chem. Soc. 1994, 116, 10801-10802.
9. (d) Miller, S. J.; Kim, S. H.; Chen, Z.-R.; Grubbs, R. H. J. Am. Chem. Soc. 1995, 36, 1169-1170.
10. (a) Wild, F. R. W. P.; Waiucionek, M.; Huttner, G.; Brintzinger, H. H. J. Organomet. Chem. 1985, 288, 63-67.
11. (b) Diamond, G. M.; Rodewald, S.; Jordan, R. F. Organometallics 1995, 14, 5-7 and references cited therein.
12. All the Zr-catalyzed reactions described herein must be carried out with freshly prepared catalyst batches of high purity. Otherwise, sluggish reactions and/or inferior enantioselectvities will be observed.
13. Final products of the tandem catalytic methathesis/ethylmagnesation protocol (e.g., 3) can serve as precursors to a large number of chiral nonracemic starting materials. For an example where nonracemic carbomagnesation adducts are used in natural product synthesis, see: Houri, A. F.; Xu, Z.-M.; Cogan, D. A.; Hoveyda, A. H. J. Am. Chem. Soc. 1995, 117, 2943-2944.
14. (a) Miller, S. J.; Grubbs, R. H. J. Am. Chem. Soc. 1995, 117, 5855-5856.
15. (b) References 5 and 8 and references cited therein.
16. 2) is notably less efficient; at 70 °C after 2 h there is only 40-50% conversion, accompanied by the formation of various byproducts.
17. For a discussion of the Thorpe - Ingold effect, see: Eliel, E. L.; Wilen, S. H.; Mander, L. N. Stereochemistry of Organic Compounds; Wiley-Imerscience: New York, 1994; pp 682-684
18. For proof of stereochemistry of 22-25, see the supporting information for ref 1a.