Mechanistic Studies of the Cu(II)-Catalyzed Electrophilic Amination

Significance

These studies are a valuable contribution to the field of electrophilic amination of non-stabilized carbanions. Evidence was found that the Cu(II)-catalyzed amination of dialkylzinc reagents follows an S_N2 pathway, as the presence of Zn(II) was not essential in the C-N bond-forming step and the reaction proceeded with retention of the configuration at the reacting carbon. In an endocyclic restriction test, the amination was shown to occur intermolecularly supporting a transition state that has a large Cu-N-OBz bond angle. The rates of the transmetallation to Cu and the C-N bond formation were found to exceed the rates of O-acylation.