Oxidative addition initiates most palladium-catalyzed cross-couplings [1] and is often rate- limiting for reactions of aryl chlorides [2] and deactivated aryl bromides.[3] This addition usually occurs to an unsaturated complex formed from ligand dissociation or after transformation of a precatalyst to the true catalyst.[4] Although the elementary oxidative addition step could occur to the same Pd0 intermediate and at the same rate when ...
