Elucidating reactivity differences in palladium-catalyzed coupling processes: The chemistry of palladium hydrides

Journal of the American Chemical Society

Volumn 126, Issue 41, 2004, Pages 13178-13179

  Hills, Ivory D ^a   Fu, Gregory C ^a  

^a MASSACHUSETTS INSTITUTE OF TECHNOLOGY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

PALLADIUM; PALLADIUM HYDRIDE; PHOSPHINE DERIVATIVE; POLYCYCLIC AROMATIC HYDROCARBON DERIVATIVE; UNCLASSIFIED DRUG;

ARTICLE; ARYLATION; CATALYST; CROSS COUPLING REACTION; CRYSTAL STRUCTURE; ELIMINATION REACTION; HECK REACTION; PHOSPHORUS NUCLEAR MAGNETIC RESONANCE; REACTION ANALYSIS; REDUCTION; SUZUKI REACTION;

ALKENES; BENZENE DERIVATIVES; CATALYSIS; CRYSTALLOGRAPHY, X-RAY; MODELS, MOLECULAR; PALLADIUM;

EID: 6044274630     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja0471424     Document Type: Article

References (25)

1. For reviews and leading references, see: (a) Negishi, E.-i., Ed. Handbook of Organopalladium Chemistry for Organic Synthesis; Wiley-Interscience: New York, 2002.
2. (b) Miyaura, N., Ed. Cross-Coupling Reactions: A Practical Guide; Topics in Current Chemistry Series 219; Springer-Verlag: New York, 2002.
3. For a review of palladium-catalyzed coupling reactions of aryl chlorides, see: Littke, A. F.; Fu, G. C. Angew. Chem., Int. Ed. 2002, 41, 4176-4211.
4. For an overview, see: Negishi, E.-i., Ed. Handbook of Organopalladium Chemistry for Organic Synthesis; Wiley-Interscience: New York, 2002; Chapter IV.
5. (a) Littke, A. F.; Fu, G. C. J. Am. Chem. Soc. 2001, 123, 6989-7000.
6. (b) Littke, A. F.; Fu, G. C. J. Org. Chem. 1999, 64, 10-11.
7. (c) For noteworthy related studies, see: Shaughnessy, K. H.; Kim, P.; Hartwig, J. F. J. Am. Chem. Soc. 1999, 121, 2123-2132 and Ehrentraut, A.; Zapf, A.; Beller, M. Synlett 2000, 1589-1592.
8. (c) For noteworthy related studies, see: Shaughnessy, K. H.; Kim, P.; Hartwig, J. F. J. Am. Chem. Soc. 1999, 121, 2123-2132 and Ehrentraut, A.; Zapf, A.; Beller, M. Synlett 2000, 1589-1592.
9. Other catalysts that effect Heck couplings of aryl chlorides have been described, but relatively high reaction temperatures are required and a limited range of reaction partners has been explored. For some early examples, see ref 2.
10. For discussions, see: (a) Grushin, V. V.; Alper, H. In Activation of Unreactive Bonds and Organic Synthesis; Murai, S., Ed.; Springer-Verlag: Berlin, 1999; pp 193-226.
11. (b) Grushin, V. V.; Alper, H. Chem. Rev. 1994, 94, 1047-1062.
12. Littke, A. F.; Fu, G. C. Angew. Chem., Int. Ed. 1998, 37, 3387-3388.
13. This difference in reactivity has been confirmed by others; for example, see: Galardon, E.; Ramdeehul, S.; Brown, J. M.; Cowley, A.: Hii, K. K.; Jutand, A. Angew. Chem., Int. Ed. 2002, 41, 1760-1763.
14. In contrast, for Heck reactions catalyzed by palladacycles, the resting state of the catalytic cycle is a species derived from the oxidative addition of Ar-X to Pd(0): Rosner, T.; Le Bars, J.; Pfaltz, A.; Blackmond, D. G. J. Am. Chem. Soc. 2001, 123, 1848-1855.
15. In a recent review of Hydridopalladium Complexes [Hii, K. K. In Handbook of Organopalladium Chemistry for Organic Synthesis; Negishi, E.-i., Ed.; Wiley-Interscience: New York, 2002; Chapter II.2.5], Hii has noted that hydridopalladium complexes "have never been detected under true catalytic conditions...The involvement of these species in the β-hydrogen elimination step is...only implied based on mechanistic considerations."
16. 4NX) may be attributable in part to efficient regeneration of Pd(0): Jeffery, T. In Advances in Metal-Organic Chemistry; Liebeskind, L. S., Ed.; JAI: London, 1996; Vol. 5, pp 153-260.
17. For reviews of palladium-hydride chemistry, see: (a) Hii, K. K. In Handbook of Organopalladium Chemistry for Organic Synthesis; Negishi, E.-i., Ed.; Wiley-Interscience: New York, 2002; Chapter II.2.5.
18. (b) Grushin, V. V. Chem. Rev. 1996, 96, 2011-2033.
19. 2NMe.
20. 2NMe (34 equiv).
21. 3, which should lead to a more stable Pd(II) complex.
22. Notes: (a) The hydrides in the crystal structures have not been located but are modeled for illustrative purposes (see the Supporting Information for details)
23. 3.
24. 31P NMR spectroscopy.
25. 2PdDCl