Regioselectivity of the nucleophilic addition to (η3-allyl) palladium complexes.: A theoretical study

Density functional calculations were performed to study the factors influencing the regioselectivity of the nucleophilic attack at allyl-Pd complexes disymmetrically substituted by electron-donating groups. The geometries of the reactants and of the products obtained after NH3 addition were fully optimized, and the transition states were localized. The more disymmetrical the allylic complex, the more regioselective the reaction toward the substituted carbon. An explanation is given based on the shapes of the LUMO and HOMO of the allylic complexes. Results in better agreement with the experiments are obtained if solvent effects are introduced.