Palladium-catalyzed arylation of linear and cyclic polyamines

The palladium-catalyzed arylation of polyamines is investigated and it is shown that the C-N coupling reaction for a given substrate is strongly dependent on the nature and the concentration of the catalytic system, as well as the nature of the base employed. The arylation of the primary amino group is favored when both primary and secondary amines are present; selective arylation is then possible without using any protecting group. The reaction of dihalobenzenes with polyamines gives the monoamination products in good yields without any significant formation of diamino compounds or reduced derivatives, unlike what is observed when monoamines are used. The extent of polyarylation of polyamines as a function of the excess of aryl halide and the nature and the amount of catalyst is also studied. Finally, N-arylation of a macrocyclic tetraamine (cyclam) is performed by using an appropriate catalytic system. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).