Direct C-arylation of free (NH)-indoles and pyrroles catalyzed by Ar-Rh(III) complexes assembled in situ

Journal of the American Chemical Society

Volumn 127, Issue 14, 2005, Pages 4996-4997

  Wang, Xiang ^a   Lane, Benjamin S ^a   Sames, Dalibor ^a  

^a Columbia University ^*  (United States)

Author keywords

[No Author keywords available]

Indexed keywords

HYDROGEN; INDOLE DERIVATIVE; NITROGEN; POLYCYCLIC AROMATIC HYDROCARBON DERIVATIVE; PYRROLE DERIVATIVE; RHODIUM COMPLEX;

ARTICLE; ARYLATION; CATALYSIS; CHEMICAL REACTION; CHEMICAL STRUCTURE; HYDROGEN BOND; REACTION ANALYSIS; STEREOCHEMISTRY; SYNTHESIS;

EID: 17144431294     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja050279p     Document Type: Article

References (14)

1. N-arylation is well established. For lead references, see: (a) Hartwig, J. F.; Kawatsura, M.; Hauck, S. I.; Shaughnessy, K. H.; Alcazar-Roman, L. M. J. Org. Chem. 1999, 64, 5575.
2. (b) Klapars, A.; Antilla, J. C.; Huang, X.; Buchwald, S. L. J. Am. Chem. Soc. 2001, 123, 7727.
3. (a) Sezen, B.; Sames, D. J. Am. Chem. Soc. 2003, 125, 5274.
4. (b) Sezen, B.; Sames, D. Org. Lett. 2003, 5, 3607.
5. For work of others, see: Rieth, R. D.; Mankad, N. P.; Calimano, E.; Sadighi, J. P. Org. Lett. 2004, 6, 3981.
6. These methods require rigorously anhydrous conditions (solvent, glassware) and very pure azole substrates.
7. For the same reason, imidazole and pyrazole were inert. For a complete list of substrates, see Supporting Information.
8. Baranano, D.; Hartwig, J. F. J. Am. Chem. Soc. 1995, 117, 2937.
9. It should be noted that this mechanism differs significantly from that proposed for the rhodium-catalyzed arylation of benzimidazole and benzoxazole at the 2-position (electron-deficient position), wherein C-H bond activation takes place first, generating a Rh(I)-carbene complex, followed by the oxidative addition of iodobenzene. Lewis, J. C.; Wiedemann, S. H.; Bergman, R. G.; Ellman, J. A. Org. Lett. 2004, 6, 35.
10. No mechanistic data have been generated for Rh-catalyzed directed orthoarylation: (a) Sezen, B.; Sames, D. J. Am. Chem. Soc. 2003, 125, 10580.
11. (b) Bedford, R. B.; Limmert, M. E. J. Org. Chem. 2003, 68, 8669.
12. The importance of carboxylate ligands in the context of palladium-mediated C-H bond activation has been discussed, however, no direct evidence has been provided. Sokolov, V. I.; Troitskaya, L. L.; Reutov, O. A. J. Organomet. Chem. 1979, 182, 537.
13. Involvement of ArPd-OR species (R = Ac, Alk, H) in other cross-coupling reactions has been proposed: (a) Miyaura, N.; Yamada, K.; Suginome, H.; Suzuki, A. J. Am. Chem. Soc. 1985, 107, 972.
14. (b) Mann, G.; Hartwig, J. F. J. Am. Chem. Soc. 1996, 118, 13109.