The nucleophilic substitution route. A facile method for the fourfold functionalization of the methylene bridges of calix[4]arene

Organic Letters

Volumn 9, Issue 15, 2007, Pages 2927-2929

  Columbus, Ishay ^a,b   Biali, Silvio E ^a  

^a HEBREW UNIVERSITY OF JERUSALEM   (Israel)

^b ISRAEL INSTITUTE FOR BIOLOGICAL RESEARCH   (Israel)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 34547141186     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol0713178     Document Type: Article

References (19)

1. For reviews on calixarenes see: (a) Gutsche, C. D. Calixarenes Revisited; Royal Society of Chemistry: Cambridge, UK, 1998.
2. (b) Calixarenes 2001; Asfari, Z., Böhmer, V., Harrowfield, J., Vicens, J., Eds.; Kluwer Academic Publishers: Dordrecht, The Netherlands, 2001.
3. (c) Böhmer, V. In The Chemistry of Phenols; Rappoport, Z., Ed.; Wiley: Chichester, UK, 2003; Chapter 19.
4. (a) Tabatai, M.; Vogt, W.; Böhmer, V. Tetrahedron Lett. 1990, 31, 3295.
5. (b) Middel, O.; Greff, Z.; Taylor, N. J.; Verboom, W.; Reinhoudt, D. N.; Snieckus, V. J. Org. Chem. 2000, 65, 667.
6. (c) Scully, P. A.; Hamilton, T. M.; Bennett, J. L. Org. Lett. 2001, 3, 2741.
7. (d) Agbaria, K.; Biali, S. E. J. Am. Chem. Soc. 2001, 123, 12495.
8. (e) Kuno, L.; Seri, N.; Biali, S. E. Org. Lett. 2007, 9, 1577.
9. We use the term "classical" to designate calixarenes possessing methylene groups as opposed to "thiacalixarenes" (sulfur bridges) and "azacalixarenes" (nitrogen atoms). For an example of an azacalixarene substituted at the four nitrogen bridges see: Tsue, H.; Ishibashi, K.; Takahashi, H.; Tamura, R. Org. Lett. 2005, 7, 2165.
10. Görmar, G.; Seiffarth, K.; Schultz, M.; Zimmerman, J.; Flämig, G. Makromol. Chem. 1990, 191, 81.
11. (a) Klenke, B.; Näther, C.; Friedrichsen, W. Tetrahedron Lett. 1998, 39, 8967.
12. (b) Kumar, S. K.; Chawla, H. M.; Varadarajan, R. Tetrahedron Lett. 2002, 43, 7073.
13. 3): δ 7.27 (s, 8H), 6.71 (s, 4H), 3.99 (s, 12H), 1.11 (s, 36H) ppm. Reported (ref 4b): δ ;8.06-7.41 (m, 8H), 6.5-4.96 (m, 4H), 3.97-3.02 (m, 12H), 1.33 (s, 36H).
14. 3) but rather that the chemical shift of the methine protons is mainly sensitive to the nature of the alkoxy group attached.
15. 19F spectrum while the tris-(trifluoroethoxy) monoethoxy derivative should display two signals. The rest of the products should display a single signal each.
16. For a review on the synthetic uses of azides see: Scriven, E. F. V.; Turnbull, K. Chem. Rev. 1988, 88, 297.
17. It may be possible that the absence of stereoselectivity is related to the small size of the azide ion as well as its high reactivity toward carbocations.
18. Hofmann, M.; Hampel, N.; Kanzian, T.; Mayr, H. Angew. Chem., Int. Ed. 2004, 43, 5402.
19. Hart, H.; Nwokogu, G. J. Org. Chem. 1981, 46, 1251.