Rh-catalyzed cyclization of diynes and enynes initiated by carbonyl-directed activation of aromatic and vinylic C-H bonds

Organic Letters

Volumn 9, Issue 16, 2007, Pages 3097-3099

  Tsuchikama, Kyoji ^a   Kuwata, Yusuke ^a   Tahara, Yu Ki ^a   Yoshinami, Yusuke ^a   Shibata, Takanori ^a  

^a WASEDA UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 34547957272     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol0711669     Document Type: Article

References (26)

1. For C-H activation reviews, see: (a) Kakiuchi, F.; Chatani, N. Adv. Synth. Catal. 2003, 345, 1077.
2. (b) Ritleng, V.; Sirlin, C.; Pfeffer, M. Chem. Rev. 2002, 102, 1731.
3. (c) Kakiuchi, F.; Murai, S. Activation of Unreactive Bonds and Organic Synthesis; Springer: Berlin, 1999.
4. (d) Dyker, G. Angew. Chem., Int. Ed. 1999, 38, 1699.
5. (e) Guari, Y.; Sabo-Etienne, S.; Chaudret, B. Eur. J. Inorg. Chem. 1999, 1047.
6. Jordan, R. F.; Taylor, D. F. J. Am. Chem. Soc. 1989, 111, 778.
7. Moore, E. J.; Pretzer, W. R.; O'Connell, T. J.; Harris, J.; LaBounty, L.; Chou, L.; Grimmer, S. S. J. Am. Chem. Soc. 1992, 114, 5888.
8. Murai, S.; Kakiuchi, F.; Sekine, S.; Tanaka, Y.; Kamatani, A.; Sonoda, M.; Chatani, N. Nature 1993, 366, 529.
9. Trost, B. M.; Imi, K.; Davies, I. W. J. Am. Chem. Soc. 1995, 117, 5371.
10. Jun, C-H.; Hong, J.-B.; Kim, Y.-H.; Chung, K.-Y. Angew. Chem., Int. Ed. 2000, 39, 3440.
11. (a) Satoh, T.; Kawamura, Y.; Miura, M.; Nomura, M. Angew. Chem., Int. Ed. Engl. 1997, 36, 1740.
12. (b) Oi, S.; Watanabe, S.-i.; Fukita, S.; Inoue, Y. Tetrahedron Lett. 2003, 44, 8665.
13. 3-H bond activation along with the C-C bond formation was also reported, see: Giri, R.; Maugel, N.; Li, J.-J.; Wang, D.-H.; Breazzano, S. P.; Saunders, L. B.; Yu, J.-Q. J. Am. Chem. Soc. 2007, 129, 3510 and references cited therein.
14. Rh-catalyzed highly enantioselective cyclization initiated by directed C-H bond activation of aromatic imines, see: Thalji, R. K.; Ellman, J. A.; Bergman, R. G. J. Am. Chem. Soc 2004, 126, 7192.
15. During the preparation of this manuscript, Tanaka, and coworkers reported the Rh-catalyzed, hydroarylative cyclization of diynes with aryl ketones, and they proposed a metallacyclopentadiene as an intermediate without direct proof, see: Tanaka, K.; Otake, Y.; Wada, A.; Noguchi, K.; Hirano, M. Org. Lett. 2007, 9, 2203.
16. (a) Tsuchikama, K.; Kuwata, Y.; Shibata, T. J. Am. Chem. Soc. 2006, 128, 13686.
17. (b) Tsuchikama, K.; Yoshinami, Y.; Shibata, T. Synlett 2007, 1395.
18. 2 (0.7 mL) was added dropwise over 30 min at room temperature, and the mixture was stirred for 5 min. After completion of the reaction, the solvent was removed under reduced pressure, and the crude products were purified by thin-layer chromatography (hexane/AcOEt = 4/1) to give pure 3aa (40.0 mg, 87%).
19. These compounds were primary products because the E/Z ratios were not changed if they were heated in 1,2-dichloroethane at 40 °C for 24 h.
20. Even using Rh-BIPHEP catalyst, no isomerization of C-C double bond, derived from C-C double bond of chalcone, was observed in product 5ad.
21. Under the same reaction conditions, the [2 + 2 + 2] cycloaddition of carbon-tethered enyne 4c with methyl acrylate or methyl pyruvate did not proceed, where metallacyclopentene would be an intermediate. These results indicate that the metallacyclopentene would not be an intermediate for the formation of present hydroarylative cycloadduct 5cd.
22. In place of diynes, tolan as a monoyne also reacted with benzophenone using the same catalyst at higher temperature to give the hydroarylated product 7 in good yield. This result shows that C-H bond cleavage surely occurred without the formation of metallacyclopentadiene intermediate. Figure Presented
23. An example of hydrorhodation of arylrhodium hydride complex to an alkyne: Jones, W. D.; Chandler, V. L.; Feher, F. J. Organometallics 1990, 9, 164.
24. This isomerization mechanism via carbene complex was already reported, see: (a) Tanke, R. S.; Crabtree, R. H. J. Am. Chem. Soc 1990, 112, 7984.
25. (b) Ojima, I.; Clos, N.; Donovan, R. J.; Ingallina, P. Organometallics 1990, 9, 3127.
26. The reaction mechanism involving the oxidative coupling of diynes or enynes could not be wholly ruled out but it cannot give reasonable explanations for the C-C double bond isomerization, which depends on the substrates.