Innovative methodologies for the N-protection of N-alkylimidazole groups: Application to the first synthesis of a water-soluble calix[6]arene presenting three ammonium substituents at the large rim and three neutral N-donors at the small rim

Organic Letters

Volumn 9, Issue 17, 2007, Pages 3271-3274

  Coquière, David ^a   Marrot, Jérôme ^b   Reinaud, Olivia ^a  

^a UNIVERSITÉ PARIS DESCARTES   (France)

^b UNIVERSITÉ DE VERSAILLES SAINT QUENTIN EN YVELINES   (France)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 34548159475     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol071208t     Document Type: Article

References (21)

1. (a) Gutsche, C. D. Calixarenes Revisited, Monographs in Supramolecular Chemistry; Stoddart, J. F., Ed.; The Royal Society of Chemistry: Cambridge, U.K., 1998.
2. (b) Calixarenes 2001; Asfari, Z., Böhmer, V., Harrowfield, J., Vicens, J., Eds.; Kluwer Academic Publishers: Dordrecht, The Netherlands, 2001.
3. (c) Calixarenes in the Nanoworld; Harrowfield, J., Vicens, J., Eds.; Springer, Dordrecht: The Netherlands, 2006.
4. Redon, S.; Li, Y.; Reinaud, O. J. Org. Chem. 2003, 68, 7004-7008.
5. Coquière, D.; Cadeau, H.; Rondelez, Y.; Giorgi, M.; Reinaud, O. J. Org. Chem. 2006, 71, 4059-4065.
6. Houmadi, S.; Coquière, D.; Legrand, L.; Fauré, M. C.; Goldmann, M.; Reinaud, O.; Rémita, S. Langmuir 2007, 23, 4849-4855.
7. Protecting Groups in Organic Synthesis; Greene, T. W., Wuts, P. G. M., Eds.; Wiley: New York, 1999.
8. A classical strategy consists of first protecting the secondary nitrogen atom of the imidazole, then alkylating the imino nitrogen to finally withdraw the protecting group (see ref 5). This sequence, which often results in poor yields, is not applicable to an imidazole group that is already N-functionalized. For an illustrative example, see: Pappo, D.; Shimony, S.; Kashman, Y. J. Org. Chem. 2005, 70, 199-206.
9. (a) Sénèque, O.; Rager, M. N.; Giorgi, M.; Reinaud, O. J. Am. Chem. Soc. 2000, 122, 6183-6189.
10. (b) Sénèque, O.; Giorgi, M.; Reinaud, O. Chem. Commun. 2001, 984-985.
11. (c) Sénèque, O.; Rager, M. N.; Giorgi, M.; Reinaud, O. J. Am. Chem. Soc. 2001, 123, 8442-8443.
12. (d) Seneque, O.; Giorgi, M.; Reinaud, O. Supramol. Chem. 2003, 15, 573-580.
13. Reinaud, O.; Le Mest, Y.; Jabin, I. Supramolecular models of metalloenzyme active sites. In Calixarenes in the Nanoworld; Harrowfield, J., Vicens, J., Eds.; Springer, Dordrecht: The Netherlands, 2006; Chapter 13.
14. Janssen, R. G.; Verboom, W.; Reinhoudt, D. N.; Casnati, A.; Freriks, M.; Pochini, A.; Ugozzoli, F.; Ungaro, R.; Nieto, P. M.; Carramolino, M.; Cuevas, F.; Prados, P.; de Mendoza, J. Synthesis 1993, 380-386.
15. Coquière, D.; Marrot, J.; Reinaud, O. Chem. Commun. 2006, 3924-3926.
16. Le Clainche, L.; Giorgi, M.; Reinaud, O. Inorg. Chem. 2000, 39, 3436-3437.
17. Sénèque, O.; Campion, M.; Giorgi, M.; Le Mest, Y.; Reinaud, O. Eur. J. Inorg. Chem. 2004, 1817-1826.
18. A few articles have reported the formation of boron derivatives, but not as a protective group. See: (a) Wacker, A.; Pritzkow, H.; Siebert, W. Eur. J. Inorg. Chem. 1999, 789-793 and refs cited therein.
19. (b) Bhaumik, J.; Yao, Z.; Borbas, K. E.; Taniguchi, M.; Lindsey, J. S. J. Org. Chem. 2006, 71, 8807-8817. The synthesis of cyanoborane adducts of 2′-deoxynucleosides has also been reported:
20. (c) Sood, A.; Spielvogel, B. F.; Shaw, B. R. J. Am. Chem. Soc. 1989, 111, 9234-9235.
21. 2O displays a profile similar to the one in DMSO. See the Supporting Information.