Air-Stable Precatalysts for Amination

By: Dr. Josephine Nakhla, Chemfiles Volume 10 Article 1

       Dr. Josephine Nakhla

Dr. Josephine Nakhla
Product Manager
Email: josephine.nakhla@sial.com

C–N bond forming cross-couplings typically require a palladium (Pd) source along with the associated ligands. Most Pd(0) sources are not air-stable, while the commonly employed air-stable Pd(0) source, Pd2(dba)3, contains associated ligands which could impede the reaction. Stable Pd(II) precursors require reduction under the reaction conditions. In either case, a ligand must be added to the reaction in order to lead to the active Pd-species. Buchwald and coworkers recently reported the use of highly-active air- and moisture-stable precatalysts, which, under the standard reaction conditions, form the active monoligated Pd-species directly. These precatalysts are exceptionally efficient even under challenging conditions, such as coupling electron-poor anilines with deactivated aryl chlorides (Scheme 1). These catalyst precursors also offer other advantages including low catalyst loadings and short reaction times.1

Scheme 1: The use of (704954) in N-arylations of electron-poor amines with electron-rich aryl chlorides.

Scheme 1: The use of (704954) in N-arylations of electron-poor amines with electron-rich aryl chlorides.


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Materials

     

References

  1. Biscoe, M. R. et al. J. Am. Chem. Soc. 2008, 130, 66

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