Quantum theory in organic chemistry: Electronic structure and chemical reactivity of (π‐allyl)palladium complexes

Abstract

By taking the palladium-catalyzed additions of nucleophiles to the coordinated allyls, we discuss the effect of ancillary ligands on the regioselectivity of the reactions. The electronic structure of (π-allyl)palladium complexes is investigated by applying the configuration analysis and the paired interaction orbital scheme. The effect of ligands upon the reactivity of carbons is examined by using the concept of the local electron-accepting ability of the reaction sites. In the complex having phosphine ligands, the terminal carbons of the allyl moiety are shown to have a higher ability for electron acceptance. The electrophilicity of the central carbon is enhanced in the complex having amine ligands, comparable to that of the terminal carbons. Finally, we show that the local electron-accepting ability is controlled by the electronegativity and the acidic hardness of each site. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 74: 735–744, 1999