Relative rates for the amination of eta3-allyl and eta3-benzyl complexes of palladium.
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.
Johns
Adam M
AM
Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, USA.
Tye
Jesse W
JW
Hartwig
John F
JF
D000586:Amination; D008024:Ligands; D008956:Models, Chemical; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*
D008024:Ligands; D010165:Palladium