On-water chemistry: Copper-catalyzed straightforward synthesis of benzo[b]furan derivatives in neat water

Organic Letters

Volumn 8, Issue 7, 2006, Pages 1467-1470

  Carril, Mónica ^a   SanMartin, Raul ^a   Tellitu, Imanol ^a   Domínguez, Esther ^a  

^a UNIVERSITY OF THE BASQUE COUNTRY UPV EHU   (Spain)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 33645910529     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol060274c     Document Type: Article

References (22)

1. (a) Narayan, S.; Muldoon, J.; Finn, M. G.; Fokin, V. V.; Kolb, H. C.; Sharpless, K. B. Angew. Chem., Int. Ed. 2005, 44, 3275 and references therein.
2. (b) Li, C.-J. Chem. Rev. 2005, 105, 3095.
3. For a review on palladium-catalyzed reactions in aqueous media, see: (a) Genet, J. P.; Savignac, M. J. Organomet. Chem. 1999, 576, 305.
4. For other metal-catalyzed protocols, see: (b) Willis, M. C.; Taylor, D.; Gillmore, A. T. Org. Lett. 2004, 6, 4755.
5. (c) Sanz, R.; Castroviejo, M. P.; Fernández, Y.; Fañanas, F. J. J. Org. Chem. 2005, 70, 6548.
6. (d) Nakamura, I.; Mizushima, Y.; Yamamoto, Y. J. Am. Chem. Soc. 2005, 127, 15022.
7. Carril, M.; SanMartin, R.; Churruca, F.; Tellitu, I.; Domínguez, E. Org. Lett. 2005, 7, 4787.
8. While this work was being carried out, an elegant protocol for the synthesis of benzo[b]furans based on copper catalysis has been recently reported, but in the absence of water (DMF was the solvent employed). See: Chen, C.-Y.; Dormer, P. G. J. Org. Chem. 2005, 70, 6964.
9. (a) Lipshutz, B. H. Chem. Rev. 1986, 86, 795.
10. (b) Fuerst, D. E.; Stoltz, B. M.; Wood, J. L. Org. Lett. 2000, 2, 3521.
11. Navarro, E.; Alonso, S. J.; Trujillo, J.; Jorge, E.; Pérez, C. J. Nat. Prod. 2001, 64, 134.
12. Kraus, G. A.; Kim, I. Org. Lett. 2003, 5, 1191.
13. Lu, H.; Liu, G.-T. Planta Med. 1992, 58, 311.
14. (a) Sun, M.; Zhao, C.; Gfesser, G. A.; Thiffault, C.; Miller, T. R., Marsh, K.; Wetter, J.; Curtis, M.; Faghih, R.; Esbenshade, T. A.; Hancock, A. A.; Cowart, M. J. Med. Chem, 2005, 48, 6482.
15. (b) Inoue, M.; Carson, M. W.; Frontier, A. J.; Danishetsky, S. J. J. Am. Chem. Soc. 2001, 123, 1878.
16. The most common approach to these heterocycles consists of the palladium-catalyzed cyclization of the corresponding 2-(1-alkynyl)phenols. See: (a) Yue, D.; Yao, T.; Larock, R. C. J. Org. Chem. 2005, 70, 10292 and references therein.
17. For other methodologies, see: (b) Kraus, G. A.; Schroeder, J. D. Synlett 2005, 2504.
18. (c) Katritzky, A. R.; Ji, Y.; Fang, Y.; Prakash, I. J. Org. Chem. 2001, 66, 5613.
19. (d) For a recent contribution of our group to the synthesis of 2,3-diarylbenzofurans and phenanthrofurans based on a palladium-catalysed tandem C-/O-arylation. see: Churruca, F.; San Martin, R.; Tellitu, I.; Domínguez, E. Eur. J. Org. Chem. 2005, 12, 2481.
20. Such complexes have been previously reported for being involved in other copper-catalyzed coupling reactions and are probably responsible for the color of the solution. See: Kaplars, A.; Huang, X.; Buchwald, S. L. J. Am. Chem. Soc. 2002, 124, 7421.
21. (a) Kwong, F. Y.; Kaplars, A.; Buchwald, S. L. Org. Lett. 2002, 4, 581.
22. (b) Gujadhur, R.; Venkataraman, D.; Kintigh, J. T. Tetrahedron Lett. 2001, 42, 4791.