Carboxylate directed cross-coupling reactions in the synthesis of trisubstituted benzoic acids

Organic Letters

Volumn 10, Issue 24, 2008, Pages 5601-5604

  Houpis, Ioannis N ^a   Huang, Changkang ^b   Nettekoven, Ulrike ^c   Chen, Jason G ^b   Liu, Renmao ^b   Canters, Martine ^a  

^a JANSSEN RESEARCH AND DEVELOPMENT   (Belgium)

^b WUXI APPTEC   (China)

^c SOLVIAS AG   (Switzerland)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 60949085731     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol802349u     Document Type: Article

References (26)

1. Directed orthometalation reactions: (a) Anctil, E.; Snieckus, V. J. Organomet. Chem. 2002, 653, 150.
2. (b) Anctil, E. J.-G.; Snieckus, V. In Metal-Catalyzed Cross Couping Reactions, 2nd ed.; Diedrich, F., De Meijere, A., Eds.; Wiley: New York, 2004; pp 761-814.
3. (c) Whisler, M. C.; MacNeil, S.; Snieckus, V.; Beak, P. Angew. Chem., Int. Ed. 2004, 43, 2206.
4. Directed hydrogenations: Crabtree, R. H.; Davies, M. W. J. Org. Chem. 1986, 51, 2655.
5. Reviews: (a) Dick, A. R.; Sanford, M. S. Tetrahedron 2006, 62, 2439.
6. (b) u, J.-Q.; Giri, R.; Chen, X. Org. Biomol. Chem. 2006, 4, 4041.
7. For initial reports of the carboxylate directing effect, see: (a) Maehara, A; Tsurugi, H; Satoh, T.; Miura, M. Org. Lett. 2008, 10, 1159.
8. (b) Ueura, K.; Satoh, T.; Miura, M. Org. Lett. 2007, 9, 1407.
9. (c) Tanaka, D.; Stuart, S. P.; Myers, A. G. J. Am. Chem. Soc. 2005, 127, 10323.
10. (d) 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.
11. (e) Mei, T.-S.; Giri, R.; Maugel, N.; Yu, J.-Q. Angew. Chem., Int. Ed. 2008, 47, 5215.
12. (f) Chiong, H. A.; Pham, Q.-N.; Daugulis, O. J. Am. Chem. Soc. 2007, 129, 9879.
13. Review: (g) Li, B.-J.; Yang, S.-D.; Shi, Z.-J. Synlett 2008, 15, 949.
14. (h) For Cu-catalyzed carboxylate-directed aminations, see: Wolf, C.; Liu, S.; Mei, X.; August, A. T.; Casimir, M. D. J. Org. Chem. 2006, 71, 3270.
15. Houpis, I. N.; Van Hoeck, J.-P.; Tilstam, U. Synlett 2007, 14, 2179.
16. Although there are several examples where the carboxylate and amide functions facilitate the ortho substitution (e.g., refs 1 and 3h), we have not seen any studies in the literature where two electronically similar halides can be differentiated.
17. The PEPPSI catalyst is marketed by Aldrich and has been used successfully in Suzuki, Negishi, and Kumada coupling reactions. (7) Use of a representative sample of the pioneering ligands developed by the Buchwald and Fu groups (several of them available in ligand kits by Strem) gave either poor conversion and/or poor selectivity: (a) Littke, A. F.; Fu, G. C. Angew. Chem., Int. Ed. 1999, 38, 2411.
18. (b) Wolfe, J. P.; Buchwald, S. L. Angew. Chem., Int. Ed. 1999, 121, 2413.
19. Several studies indicate that a number of cross-coupling reactions proceed via Pd nanoparticles: de Vries, J. Dalton Trans. 2006, 421.
20. Proof of regiochemistry was performed for all compounds. For representative examples, see the Supporting Information.
21. In the absence of water, the reaction does not proceed, irrespective of the base or catalyst used.
22. Pd-black precipitated almost immediately when the reaction reached optimal reaction temperature (ca. 65 °C).
23. The resulting carboxylate palladacycles have only been reported only recently and are not commonly used. They have been shown to be competent catalysts (e.g., for carbonylation reactions): (Chemical Equation Presented) (a) Nagayama, K.; Kawataka, F.; Sakamoto, M.; Shimizu, I.; Yamamoto, A. Bull. Chem. Soc. Jpn. 1999, 72, 573.
24. Other oxapalladecycles: (b) Fernandez-Rivas, C.; Cardenas, D. J.; Maertin-Matute, B.; Monge, A.; Gutierrez-Puebla, E.; Echavarren, A. M. Organometallics 2001, 20, 2998.
25. A recent, thorough, review on palladacycles did not report any synthetic utility of carboxylate palladacycle species: (c) Dupont, J.; Consorti, C. S. Chem. Rev. 2005, 105, 2527.
26. 3 (0.5-1 mol % depending on the substrate) was added under an argon blanket, and the reaction mixture was heated to 65 °C for ca. 16-36 h (depending on substrate). After ca. 30 min, the deep purple color of the precatalyst turned pale yellow. This color persisted throughout the reaction. Alternatively, the catalyst can be added at the reaction temperature without major differences in the reaction outcome. Upon completion (as judged by HPLC analysis at 230 nm), the reaction mixture was subjected to an acidic aqueous workup (2-Me-THF or MTBE were used), and the organic layer was concentrated in vacuo. Flash chromatography using the appropriate mixture of ethyl acetate and heptane (depending on the substrate) afforded the product.