Matching the chirality of monodentate N-heterocyclic carbene ligands: A case study on well-defined palladium complexes for the asymmetric α-arylation of amides

Organic Letters

Volumn 10, Issue 24, 2008, Pages 5569-5572

  Luan, Xinjun ^a   Mariz, Ronaldo ^a   Robert, Carine ^a   Gatti, Michele ^a   Blumentritt, Sascha ^a   Linden, Anthony ^a   Dorta, Reto ^a  

^a UNIVERSITY OF ZURICH   (Switzerland)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 60949084790     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol8021808     Document Type: Article

References (23)

1. (a) N-Heterocyclic Carbenes in Synthesis; Nolan, S. P., Ed.; Wiley-VCH: Weinheim: Germany, 2006.
2. (b) N-Heterocyclic Carbenes in Transition Metal Catalysis; Glorius, F., Ed.; Topics in Organometallic Chemistry, Vol. 21; Springer: Berlin, 2007.
3. Cesar, V.; Bellemin-Laponnaz, S.; Gade, L. H. Chem. Soc. Rev. 2004, 33, 619.
4. (a) Ma, Y.; Song, C.; Ma, C.; Sun, Z.; Chai, Q.; Andrus, M. B. Angew. Chem., Int. Ed. 2003, 42, 5871.
5. (b) Song, C.; Ma, C.; Ma, Y.; Feng, W.; Ma, S.; Chai, Q.; Andrus, M. B. Tetrahedron Lett. 2005, 46, 3241.
6. (a) Seiders, T. J.; Ward, D. W.; Grubbs, R. H. Org. Lett. 2001, 3, 3225.
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8. (c) Berlin, J. M.; Goldberg, S. D.; Grubbs, R. H. Angew. Chem., Int. Ed. 2006, 45, 7591. For a computational study, see:
9. (d) Costabile, C.; Cavallo, L. J. Am. Chem. Soc. 2004, 126, 9592.
10. 2-symmetric chiral NHCs with aromatic side chains, see: (a) Martin, D.; Kehrli, S.; d'Augustin, M.; Clavier, H.; Mauduit, M.; Alexakis, A. J. Am. Chem. Soc. 2006, 128, 8416.
11. (b) Chaulagain, M. R.; Sormunen, G. J.; Montgomery, J. J. Am. Chem. Soc. 2007, 129, 9568.
12. (c) Matsumoto, Y.; Yamada, K.; Tomioka, K. J. Org. Chem. 2008, 73, 4578.
13. 6-coordination of the aromatic side chains, appear just as likely as coordination of the presumably deprotonated carbene moiety; see ref 3.
14. Different rotamers of NHC salts and precatalysts seem to exist; see the Supporting Information of refs 4a and 5b.
15. Luan, X.; Mariz, R.; Gatti, M.; Costabile, C.; Poater, A.; Cavallo, L.; Linden, A.; Dorta, R. J. Am. Chem. Soc. 2008, 130, 6848.
16. (a) Lee, S.; Hartwig, J. F. J. Org. Chem. 2001, 66, 3402.
17. (b) Glorius, F.; Altenhoff, G.; Goddard, R.; Lehmann, C. Chem. Commun. 2002, 2704.
18. (c) Arao, T.; Kondo, K.; Aoyama, T. Chem. Pharm. Bull 2006, 54, 1743.
19. (d) Kündig, E. P.; Seidel, T. M.; Jia, Y. X. Angew. Chem., Int. Ed. 2007, 46, 8484.
20. Because 1d performed poorly in the in situ catalysis, it was not employed further.
21. Marion, N.; Navarro, O.; Mei, J.; Stevens, E. D.; Scott, N. M.; Nolan, S. P. J. Am. Chem. Sac. 2006, 128, 4101.
22. a denote the axial chirality between the N-heterocycle and the naphthyl side chains.
23. Compound 2a performs better than the reference system (SIPr)P-d(cin)Cl; see the Supporting Information.