Interplays between Reactions within and without the Catalytic Cycle of the Heck Reaction as a Clue to the Optimization of the Synthetic Protocol

This account presents previous and recent mechanistic studies of the Heck reactions reported by the authors whose attention has been focused on a problem of the coupling of catalyst transformations within and without the catalytic cycle. Based on the understanding of the interaction mechanism between these processes a development of new methods of Heck chemistry became conceivable. In particular, such a rational approach allowed an elaboration of the ligand-free systems, which are effective not only in the reaction with non-activated aryl bromides but also with non-activated aryl chlorides.