Catalytic Oxidation of Amines Utilizing Binuclear Copper(II) Complex of 7-Azaindole

Treatment of benzylamine with a catalytic amount of a binuclear copper(II) complex of 7-azaindole 1 under an oxygen atmosphere at room temperature produced benzylidene-benzylamine and benzonitrile in good yields. This reaction is also applicable to other amines and gives the corresponding imines. Interestingly 1-phenylpyrrolidine was oxidized to cyclic dimers, but, in the presence of triethylamine, it was oxidized to the corresponding γ-lactam.