Relative rates for the amination of eta3-allyl and eta3-benzyl complexes of palladium

J Am Chem Soc. 2006 Dec 20;128(50):16010-1. doi: 10.1021/ja067084h.

Abstract

Reactions of nucleophiles with metal-bound hydrocarbyl pi-ligands bound in an eta3-fashion are key steps in a variety of carbon-carbon and carbon-heteroatom bond-forming reactions. To reveal factors that control the rates of reaction of nucleophiles with this type of ligand, the rates of reactions of an aromatic and an aliphatic amine with a series of eta3-allyl, eta3-benzyl, and eta3-phenethyl palladium complexes ligated by the bisphosphine (R)-BINAP to form allylic and benzylic amines were measured. These data showed that the less common addition to an eta3-benzyl complex is faster than the more common addition to an eta3-allyl complex. The relative rates of reaction followed the trend naphthylmethyl > naphthylethyl > benzyl > 1,1-dimethylallyl > allyl. Computational studies suggest that there is a correlation between the amount of positive charge at the site of nucleophilic attack and the rate of C-N bond formation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amination
  • Ligands
  • Models, Chemical
  • Molecular Structure
  • Palladium / chemistry*

Substances

  • Ligands
  • Palladium