Regioselectivity of Nucleophilic Attack on [Pd(allyl)(phosphine)(imine)] Complexes:  A Theoretical Study

Extended Hückel calculations help rationalize the observed regioselectivity of allylic alkylations catalyzed by Pd complexes containing either C2-symmetric or electronically asymmetric bidentate chiral ligands. Mixing of the empty high-lying π* into the LUMO, made up mostly of the antibonding combination between the dx2-y2 and the allyl nonbonding fragment orbitals, increases the electrophilicity of the carbon with the longest Pd−C bond as its weight in the LUMO increases.