Lewis acid-catalyzed nucleophilic substitutions of propargylic and allylic silyl ethers with enol silyl ethers

Organic Letters

Volumn 5, Issue 1, 2003, Pages 51-54

  Ishikawa, Teruhiko ^a   Aikawa, Toshiaki ^a   Mori, Yumiko ^a   Saito, Seiki ^a  

^a OKAYAMA UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

ALLENE DERIVATIVE; ALLYL COMPOUND; KETONE DERIVATIVE; LEWIS ACID; SILANE DERIVATIVE;

ARTICLE; CATALYSIS; CATALYST; CHEMICAL STRUCTURE; METHODOLOGY; SUBSTITUTION REACTION;

EID: 0141787115     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol0271537     Document Type: Article

References (18)

1. (a) Mukaiyama, T.; Kobayashi, S. Org. React. 1994, 46, 1-103.
2. (b) Bednarski, M. D.; Lyssikatos, J. P. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Eds.; Pergamon: Oxford, 1991; Vol. 2, Chapter 2.5.
3. (a) Itoh, A.; Oshima, K.; Yamamoto, H.; Nozaki, H. Bull. Chem. Soc. Jpn. 1980, 53, 2050-2054.
4. (b) Mayr, H.; Heilmann, W.; Lammers, R. Tetrahedron 1986, 42, 6663-6668. See also: Hibino, M.; Koike, T.; Yoshimatsu, M. J. Org. Chem. 2002, 67, 1078-1083.
5. (b) Mayr, H.; Heilmann, W.; Lammers, R. Tetrahedron 1986, 42, 6663-6668. See also: Hibino, M.; Koike, T.; Yoshimatsu, M. J. Org. Chem. 2002, 67, 1078-1083.
6. Ishikawa, T.; Okano, M.; Aikawa, T.; Saito, S. J. Org. Chem. 2001, 66, 4635-4642. Only three examples, including those shown in Scheme 1, were reported therein.
7. 2 (5 mL/l mmol of ketone) as a solvent at 0°C for 1.5 h.
8. Prepared from ketones for 2a-c or enones for 2d-h with corresponding acetylide anions followed by O-silylation; see ref 3.
9. (a) Matsuda, I.; Komori, K.; Itoh, K. J. Am. Chem. Soc. 2002, 124, 9072-9073.
10. (b) Matsuda, I.; Wakamatsu, S.; Komori, K.; Makino, T.; Itoh, K. Tetrahedron Lett. 2002, 43, 1043-1046.
11. Selectivity of this class is difficult to explain only on the basis of the steric effect, and clarification of the other factors, if any, must await future studies.
12. Similar trends were reported in alkoxide-promoted Michael addition reactions using simple ketones; for example, see: (a) House, H. O.; Roelofs, W. L.; Trost, B. M. J. Org. Chem. 1966, 31, 646-655. (b) Ishikawa, T.; Kadoya, R.; Arai, M.; Takahashi, H.; Kaisi, Y.; Mizuta, T.; Yoshikai, K.; Saito, S. J. Org. Chem. 2001, 66, 8000-8009.
13. Similar trends were reported in alkoxide-promoted Michael addition reactions using simple ketones; for example, see: (a) House, H. O.; Roelofs, W. L.; Trost, B. M. J. Org. Chem. 1966, 31, 646-655. (b) Ishikawa, T.; Kadoya, R.; Arai, M.; Takahashi, H.; Kaisi, Y.; Mizuta, T.; Yoshikai, K.; Saito, S. J. Org. Chem. 2001, 66, 8000-8009.
14. 2 was used as the Lewis acid except for the case of entry 4 in Table 2, where TMSOTf was used.
15. The reason for the preferential formation of (Z)-enynes was already discussed; see ref 3.
16. Structures and isomer ratios for the products were determined by careful analysis of NMR spectra, although the relative configurations of major isomers were not determined yet; see also Supporting Information.
17. Reactions of 11 with 2a,d, 2i with 1a, and 2j with 1a,d did not take place under the given reaction conditions.
18. Denmark, S. E.; Pham, S. M. Org. Lett. 2001, 3, 2201-2204.