New versatile Pd-catalyzed alkylation of indoles via nucleophilic allylic substitution: Controlling the regioselectivity

Organic Letters

Volumn 6, Issue 18, 2004, Pages 3199-3202

  Bandini, Marco ^a   Melloni, Alfonso ^a   Umani Ronchi, Achille ^a  

^a UNIVERSITY OF BOLOGNA   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

ALKALOID DERIVATIVE; CARBONIC ACID DERIVATIVE; INDOLE DERIVATIVE; PALLADIUM;

ALKYLATION; ARTICLE; CATALYSIS; SUBSTITUTION REACTION;

ALKYLATION; CARBONATES; CATALYSIS; INDOLE ALKALOIDS; INDOLES; MOLECULAR STRUCTURE; PALLADIUM;

EID: 4544324311     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol048663z     Document Type: Article

References (33)

1. Sundberg, R. J. In Indoles; Academic Press: San Diego, 1996.
2. Yamamoto, H. In Lewis Acids in Organic Synthesis; Wiley-VCH: Weinheim, 2000.
3. Antilla, J. C.; Klapars, A.; Buchwald, S. L. J. Am. Chem. Soc. 2002, 124, 11684-11688 and references therein.
4. (a) Billups, W. E.; Erkes, R. S.; Reed, L. E. Synth. Commun. 1980, 10, 147-151.
5. (b) Trost, B. M.; Molander, G. A. J. Am. Chem. Soc. 1981, 103, 5969-5972.
6. (c) Bourak, M.; Gallo, R. Heterocycles 1990, 31, 447-457,
7. (d) Zhu, X.; Ganesan, A. J. Org. Chem. 2002, 67, 2705-2708.
8. (e) Yadav, J. S.; Reddy, B. V. S.; Muralikrishna Reddy, P.; Srinivas, Ch. Tetrahedron Lett. 2002, 43, 5185-5187.
9. (f) Trost, B. M.; Krische, M. J.; Berl, V.; Grenzer, E. M. Org. Lett. 2002, 4, 2005-2008.
10. (a) Moreno-Mañas, M.; Pleixats, R. Adv. Heteroycl. Chem. 1996, 66, 73-129 and references therein.
11. (b) Trost, B. M.; Van Vraken, D. L. Chem. Rev. 1996, 96, 395-422.
12. (c) Trost, B. M.; Crawley, M. L. Chem. Rev. 2003, 103, 2921-2944.
13. Nunomoto, S.; Kawakami, Y.; Yamashita, Y.; Takeuchi, H.; Eguchi, S. J. Chem. Soc., Perkin Trans. 1 1990, 111-114.
14. Malkov, A. V.; Davis, S. L.; Baxendale, I. R.; Mitchell, W. L.; Kočovský, P. J. Org. Chem,. 1999, 64, 2751-2764.
15. 3]·CHCh, a significant amount of 1,4-addition of indole to the dba (dibenzylidenacetone) was detected. For a related case, see: Bandini, M.; Cozzi, P. G.; Giacomini, M.; Melchiorre, P.; Selva, S.; Umani-Ronchi, A. J. Org. Chem. 2002, 67, 3700-3704.
16. Trost, B. M.; Fraisse, P. L.; Ball, Z. T. Angew. Chem., Int. Ed. 2002, 41, 1059-1061.
17. 2 in the presence of silica, reflux 24 h, convn >90%). On the other hand, carbonates 2c-e and 12 (vide infra), less prone to originate carbocationic species respect to 2a, did not undergo the present indole alkylation in any extent under the above-mentioned conditions. For a related study, see: Bisaro, F.; Prestat, G.; Vitale M.; Poli, G. Synlett 2002, 1823-1826.
18. For a related study concerning the synthesis of 3-allylindoles by Pd-catalyzed cyclization of alkynyltrifluoroacetanilidenes, see: Cacchi, S.; Fabrizi, G.; Pace, P. J. Org. Chem. 1998, 63, 1001-1011.
19. (a) Hogen-Esch, T. E.; Smid, J. J. Am. Chem. Soc. 1965, 87, 669-670.
20. (b) Zaugg, H. E.; Schaefer, A. D. J. Am. Chem. Soc. 1965, 87, 1857-1866.
21. (c) Hogen-Esch, T. E.; Smid, J. J. Am. Chem. Soc. 1966, 88, 307-318.
22. (d) Powers, J. C.; Meyer, W. P.; Parsons, T. G. J. Am. Chem. Soc. 1967, 89, 5812-5820.
23. (e) Buncel, E.; Menon, B. J. Org. Chem. 1979, 44, 317-320.
24. In some cases, with carbonate 2c the product of N/C-dialkylation was also isolated from the crude mixture (5-10%).
25. 3) furnished a complex mixture of N- and C-products in low yield and poor regioselectivity. (Chemical Equation Presented)
26. For recent reports of Pd- and Pt-catalyzed intramolecular alkylation of indoles with unactivated olefins, see: (a) Ferreira, E. M.; Stoltz, B. M. J. Am. Chem. Soc. 2003, 125, 9578-9579. (b) Abbiati, G.; Beccalli, E. M.; Broggini, G.; Zoni, C. J. Org. Chem. 2003, 68, 7625-7628. (c) Xiaoqing, C. L.; Wang, X.; Widenhoefer, R. A. J. Am. Chem. Soc. 2004, 126, 3700-3701. (d) Liu, C.; Widenhoefer, R. A. J. Am. Chem. Soc. 2004, 126, 10250-10251.
27. For recent reports of Pd- and Pt-catalyzed intramolecular alkylation of indoles with unactivated olefins, see: (a) Ferreira, E. M.; Stoltz, B. M. J. Am. Chem. Soc. 2003, 125, 9578-9579. (b) Abbiati, G.; Beccalli, E. M.; Broggini, G.; Zoni, C. J. Org. Chem. 2003, 68, 7625-7628. (c) Xiaoqing, C. L.; Wang, X.; Widenhoefer, R. A. J. Am. Chem. Soc. 2004, 126, 3700-3701. (d) Liu, C.; Widenhoefer, R. A. J. Am. Chem. Soc. 2004, 126, 10250-10251.
28. For recent reports of Pd- and Pt-catalyzed intramolecular alkylation of indoles with unactivated olefins, see: (a) Ferreira, E. M.; Stoltz, B. M. J. Am. Chem. Soc. 2003, 125, 9578-9579. (b) Abbiati, G.; Beccalli, E. M.; Broggini, G.; Zoni, C. J. Org. Chem. 2003, 68, 7625-7628. (c) Xiaoqing, C. L.; Wang, X.; Widenhoefer, R. A. J. Am. Chem. Soc. 2004, 126, 3700-3701. (d) Liu, C.; Widenhoefer, R. A. J. Am. Chem. Soc. 2004, 126, 10250-10251.
29. For recent reports of Pd- and Pt-catalyzed intramolecular alkylation of indoles with unactivated olefins, see: (a) Ferreira, E. M.; Stoltz, B. M. J. Am. Chem. Soc. 2003, 125, 9578-9579. (b) Abbiati, G.; Beccalli, E. M.; Broggini, G.; Zoni, C. J. Org. Chem. 2003, 68, 7625-7628. (c) Xiaoqing, C. L.; Wang, X.; Widenhoefer, R. A. J. Am. Chem. Soc. 2004, 126, 3700-3701. (d) Liu, C.; Widenhoefer, R. A. J. Am. Chem. Soc. 2004, 126, 10250-10251.
30. (a) Cox, E. D.; Cook, J. M. Chem. Rev. 1995, 95, 1797-1842
31. (b) Chang-Fong, J.; Tyacke, R. J.; Lau, A.; Westaway, J.; Hudson, A. L.; Glennon, R. A. Bioorg. Med. Chem. Lett. 2004, 14, 1003-1005.
32. Suzuki, H.; Unemoto, M.; Hagiwara, M.; Ohyama, T.; Yokoyama, Y.; Murakami, Y. J. Chem. Soc., Perkin Trans. 1 1999, 1717-1724.
33. For a related Lewis acid mediated cyclization procedure see: Agnusdei, M.; Bandini. M.; Melloni, A.; Umani-Ronchi, A. J. Org. Chem. 2003, 68, 7126-7129.