The synthesis of unsymmetrical alkyldiarylamines from a primary amine and two aryl bromides is described. A catalyst system composed of Pd(OAc)(2)/(rac)-BINAP is used to prepare an alkylarylamine (1) from a primary amine and aryl bromide. The palladium-catalyzed arylation of 1, by means of a different catalyst system, affords an alkyldiarylamine. The efficiency of each catalyst for the second step depends on the electronic nature of the substrates. This method has reasonable generality and compatiblity with base-sensitive functional groups.
“Sequential N-Arylation of Primary Amines as a Route To Alkyldiarylamines”, J. Org. Chem., 1999, 64(16), 6019-6022.