Transition metal-catalysed allylic substitution is a useful process in organic synthesis, and many excellent results have been reported for the reaction of symmetrically disubstituted substrates. 1 On the other hand, the regioselective allylic substitution of unsymmetrical allyl substrates is a difficult problem and very challenging topic in this field of chemistry. In particular, it is known that the control of mono-substituted allyl substrates that forms both linear and branched ...