B(C6F5)3-catalyzed Hydrosilation of Imines via Silyliminium Intermediates

Organic Letters

Volumn 2, Issue 24, 2000, Pages 3921-3923

  Blackwell, James M ^a   Sonmor, Eric R ^a   Scoccitti, Tiziana ^a   Piers, Warren E ^a  

^a UNIVERSITY OF CALGARY   (Canada)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0001231537     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol006695q     Document Type: Article

References (23)

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2. For example, see: (a) Ishihara, K.; Yamamoto, H. Eur. J. Org. Chem. 1999, 527.
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4. (c) Gevorgyan, V.; Rubin, M.; Benson, S.; Liu, J.-X.; Yamamoto, Y. J. Org. Chem. 2000, 65, 6179.
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6. (e) Ishihara, K.; Hanaki, N.; Funahasi, M.; Miyata, M., Yamamoto, H. Bull. Chem. Soc. Jpn. 1995, 68, 1721.
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11. Stannyloxonium intermediates have, however, been observed by NMR spectroscopy, see ref 3d.
12. For recent reviews on imine reductions, see (a) Kobayashi, S.; Ishitani, H. Chem. Rev. 1999, 99, 1069.
13. (b) Hutchins, R. O.; Hutchins, M. K. Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Eds.; Pergamon Press: New York, 1991; Vol. 8, p 25.
14. For proposed intermediacy of silyliminium cations, see: (a) Jahangir; MacLean, D. B.; Brook, M. A.; Holland, H. L. J. Chem. Soc., Chem. Commun. 1986, 1608.
15. (b) Johannsen, M.; Jorgensen, K. A.; Helmchen, G. J. Am. Chem. Soc. 1998, 120, 7637. For a proposed stannyliminium intermediate, see: Suwa, T.; Shibata, I.; Nishino, K.; Baba, A. Org. Lett. 1999, 1, 1579.
16. (b) Johannsen, M.; Jorgensen, K. A.; Helmchen, G. J. Am. Chem. Soc. 1998, 120, 7637. For a proposed stannyliminium intermediate, see: Suwa, T.; Shibata, I.; Nishino, K.; Baba, A. Org. Lett. 1999, 1, 1579.
17. Silylnitrilium, silylpyridinium, and silylimidazolium cations have been characterized, see: Lambert, J. B.; Kania, L.; Zhang, S. Chem. Rev. 1995, 95, 1191 and references therein.
18. 3 has been proposed, see: Lambert, J. B.; Kuhlmann, B. J. Chem. Soc., Chem. Commun. 1992, 931. However, no direct spectral evidence has been provided yet for silanes.
19. 1H NMR then being used to assess purity (see Supporting Information).
20. For nitrogen deprotection strategies for these functional groups, see: Greene, T. W.; Wuts, P. G. Protecive Groups in Organic Synthesis, 2nd ed.; John Wiley and Sons: New York, 1991.
21. 3 adducts of imines is in preparation.
22. Lambert has also reported this behavior when generating solvent-coordinated silylium-type species, see: Lambert, J. B.; Zhang, S.; Ciro, C. M. Organometallics 1994, 13, 2430.
23. 3 derivatives, see ref 3d and references therein.