Cerium Salt Promoted Homocoupling Reaction of Dialkylanilines in Water

Highly regioselective homocoupling of N,N-dialkylanilines can be achieved in water with cerium reagents, in which various N,N,N′,N′-tetraalkylbenzidines are obtained from N,N-dialkylanilines either by direct oxidation by cerium(IV) reagents or by cerium(III) reagents in the presence of hydroperoxide.