Palladium-catalyzed amination of aryl bromides and aryl triflates using diphosphane ligands: A kinetic study

[Pd(P-O-P)(Ar)](+) complexes with ligands that have wide bite angles are ac tive catalysts fur the coupling of aniline derivatives with aryl triflates. Kinetic studies show that for these systems a fast equilibrium that involv es coordination of the amine precedes the deprotonation, which is the rate- limiting step of the reaction. This reaction is faster for compounds with a smaller P-Pd-P angle. When halide salts are present, the base sodium tert- butoxide is activated and adds to the palladium complex. This rate-limiting step is preceded by a fast equilibrium that involves decoordination of the halide. The initial reaction rate is faster for compounds with a larger P- Pd-P angle. This is due to the closer proximity of the oxygen to the Pd cen ter, and this assists in the dissociation of the halide.