o-Carborane as a Novel Protective Group for Aldehydes and Ketones

Journal of Organic Chemistry

Volumn 62, Issue 4, 1997, Pages 780-781

  Nakamura, Hiroyuki ^a   Aoyagi, Kouichi ^a   Yamamoto, Yoshinori ^a  

^a TOHOKU UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000425082     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo962130p     Document Type: Article

References (20)

1. Protective Groups in Organic Synthesis; Greene, T. W., Wuts, P. G. M., Ed.; John Wiley: New York, 1991; pp 175-223.
2. Stork, G.; Maldonado, L. J. Am. Chem. Soc. 1971, 93, 5286. Evans, D. A.; Hoffman, J. M.; Truesdale, L. K. J. Am. Chem. Soc. 1973, 95, 5822. Hiyama, T.; Oishi, H.; Saimoto, H. Tetrahedron Lett. 1985, 26, 2459. Also see ref 1.
3. Stork, G.; Maldonado, L. J. Am. Chem. Soc. 1971, 93, 5286. Evans, D. A.; Hoffman, J. M.; Truesdale, L. K. J. Am. Chem. Soc. 1973, 95, 5822. Hiyama, T.; Oishi, H.; Saimoto, H. Tetrahedron Lett. 1985, 26, 2459. Also see ref 1.
4. Stork, G.; Maldonado, L. J. Am. Chem. Soc. 1971, 93, 5286. Evans, D. A.; Hoffman, J. M.; Truesdale, L. K. J. Am. Chem. Soc. 1973, 95, 5822. Hiyama, T.; Oishi, H.; Saimoto, H. Tetrahedron Lett. 1985, 26, 2459. Also see ref 1.
5. On the other hand, the latter property can become an advantage of the protecting group. Very high asymmetric induction is accomplished by the Lewis acid-mediated reactions of chiral acetals: Mukaiyama, T. Angew. Chem., Int. Ed. Engl. 1977, 16, 817. Johnson, W. S.; Elliott, R.; Elliott, D. J. Am. Chem. Soc. 1983, 105, 2904. Johnson, W. S.; Edington, C.; Elliott, J. D.; Silverman, I. R. J. Am. Chem. Soc. 1984, 106, 7588. Yamamoto, Y.; Nishii, S.; Yamada, J. J. Am. Chem. Soc. 1986, 108, 7116. Also see the recent review: Comprehensive Organic Synthesis; Schreiber, S. L., Ed.; Pergamon Press: Oxford, 1991; Vol. 1, pp 325-354.
6. On the other hand, the latter property can become an advantage of the protecting group. Very high asymmetric induction is accomplished by the Lewis acid-mediated reactions of chiral acetals: Mukaiyama, T. Angew. Chem., Int. Ed. Engl. 1977, 16, 817. Johnson, W. S.; Elliott, R.; Elliott, D. J. Am. Chem. Soc. 1983, 105, 2904. Johnson, W. S.; Edington, C.; Elliott, J. D.; Silverman, I. R. J. Am. Chem. Soc. 1984, 106, 7588. Yamamoto, Y.; Nishii, S.; Yamada, J. J. Am. Chem. Soc. 1986, 108, 7116. Also see the recent review: Comprehensive Organic Synthesis; Schreiber, S. L., Ed.; Pergamon Press: Oxford, 1991; Vol. 1, pp 325-354.
7. On the other hand, the latter property can become an advantage of the protecting group. Very high asymmetric induction is accomplished by the Lewis acid-mediated reactions of chiral acetals: Mukaiyama, T. Angew. Chem., Int. Ed. Engl. 1977, 16, 817. Johnson, W. S.; Elliott, R.; Elliott, D. J. Am. Chem. Soc. 1983, 105, 2904. Johnson, W. S.; Edington, C.; Elliott, J. D.; Silverman, I. R. J. Am. Chem. Soc. 1984, 106, 7588. Yamamoto, Y.; Nishii, S.; Yamada, J. J. Am. Chem. Soc. 1986, 108, 7116. Also see the recent review: Comprehensive Organic Synthesis; Schreiber, S. L., Ed.; Pergamon Press: Oxford, 1991; Vol. 1, pp 325-354.
8. On the other hand, the latter property can become an advantage of the protecting group. Very high asymmetric induction is accomplished by the Lewis acid-mediated reactions of chiral acetals: Mukaiyama, T. Angew. Chem., Int. Ed. Engl. 1977, 16, 817. Johnson, W. S.; Elliott, R.; Elliott, D. J. Am. Chem. Soc. 1983, 105, 2904. Johnson, W. S.; Edington, C.; Elliott, J. D.; Silverman, I. R. J. Am. Chem. Soc. 1984, 106, 7588. Yamamoto, Y.; Nishii, S.; Yamada, J. J. Am. Chem. Soc. 1986, 108, 7116. Also see the recent review: Comprehensive Organic Synthesis; Schreiber, S. L., Ed.; Pergamon Press: Oxford, 1991; Vol. 1, pp 325-354.
9. On the other hand, the latter property can become an advantage of the protecting group. Very high asymmetric induction is accomplished by the Lewis acid-mediated reactions of chiral acetals: Mukaiyama, T. Angew. Chem., Int. Ed. Engl. 1977, 16, 817. Johnson, W. S.; Elliott, R.; Elliott, D. J. Am. Chem. Soc. 1983, 105, 2904. Johnson, W. S.; Edington, C.; Elliott, J. D.; Silverman, I. R. J. Am. Chem. Soc. 1984, 106, 7588. Yamamoto, Y.; Nishii, S.; Yamada, J. J. Am. Chem. Soc. 1986, 108, 7116. Also see the recent review: Comprehensive Organic Synthesis; Schreiber, S. L., Ed.; Pergamon Press: Oxford, 1991; Vol. 1, pp 325-354.
10. It was reported that generation of monolithiocarborane 2 by treating o-carborane with n-BuLi was accompanied by dilithiocarborane formation due to the disproportionate reaction of 2 (see Gome, F. A.; Johnson, S. E.; Hawthorne, M. F. J. Am. Chem. Soc. 1991, 113, 5915). However, we have found that the redistribution reaction can be avoided by carrying out the lithiation of o-carborane under controlled conditions (see a representative example in text).
11. o-Carborane (closo) is converted to nido-o-carborane by treatment with bases. However, under the cleavage conditions, the closo frame-work was stable to KOH.
12. Other attractive points of this protective group are that protected aldehydes and ketones 3 are readily crystallized and stable to air, moisture, and acids.
13. 4 (2 equiv) for 2 days gave no benzaldehyde, but 3b was recovered quantitatively.
14. 3) δ 7.87 (m, 3H), 7.78 (s, 1H), 7.54 (m, 2H), 7.45 (dd, J = 9.0, 2.0 Hz, 1H), 5.44 (d, J = 3.5 Hz, 1H), 3.84 (s, 1H), 2.72 (d, J = 3.5 Hz, 1H).
15. Zakharkin, L. I.; Chapovskii, Y. A. Tetrahedron Lett. 1964, 1147.
16. Zakharkin, L. I.; L'vov, A. I. J. Organomet. Chem. 1966, 5, 313.
17. Zakharkin, L. I.; Chapovskii, Y. A.; Brattsev, V. A.; Stanko, V. I. Zh. Obshch. Khim. 1966, 36, 878.
18. Carboranes Grimes, R. N., Ed.; Academic Press: New York, 1970; pp 82-115.
19. The bifunctional molecule 11 was synthesized via Heck reaction of p-bromobenzaldehyde and 5-hexen-2-one, which was prepared by the literature procedure: Buntin, S. A.; Heck, R. F. Org. Synth. 1993, 61, 82.
20. Nakamura, H.; Sadayori, N.; Sekido, M.; Yamamoto, Y. J. Chem. Soc., Chem. Commun. 1994, 2581.