Enantioselectivity of norbornadiene allylation in the presence of Pd phosphine complexes: a quantum chemical prediction

The effect of chiral phosphine ligands PR 1 R 2 R 3 (R 1 , R 2 , R 3 = Me, Pr i , Bu i , p -Tol, cyclohexyl, Ph) on the enantioselectivity of Pd-catalyzed allylation of norbornadiene (NBD) was modeled within the framework of the scalar-relativistic approximation of the density functional theory using the ωB97X-D3(BJ) functional. According to calculations, the reaction in the presence of phosphines PPh(Bu i )(Pr i ), PPh(Pr i )Me, and P(Bu i )(Pr i )Me can proceed regioselectively with respect to exo -products. In all cases, calculations predict the predominance of one of the enantiomers of the exo -product. The highest enantiomeric excess (96%) can be achieved using PPh(Pr i )Me.