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Ferrocenyl Based Ligands and Catalysts

By: Josephine Nakhla, Aldrich ChemFiles 2009, 9.2, 11.

Aldrich ChemFiles 2009, 9.2, 11.

Hartwig and co-workers have reported the use of the electron-rich and bulky ligand 1,1’-bis(di-tert-butylphosphino)ferrocene for the amination of aryl halides and for the first amination of aryl tosylates. The amination of various amines with aryl chlorides, iodides, and tosylates was effected using this novel ligand in combination with a palladium source affording the coupled products in excellent yield. This ligand is exceptionally effective and, though the electron density on the metal helps accelerate the oxidative addition (a necessity for unactivated aryl chlorides), the electron-richness does not negatively impact the reductive elimination since the steric bulk associated with this ligand facilitates this last step of the catalytic cycle (Table 4).1


Table 4.

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Materials

     

References

  1. Hamann, B. C.; Hartwig, J. F. J. Am. Chem. Soc. 1998, 120, 7369.

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