We Already Know Everything about Oxidative Addition to Pd(0): Do We?

The oxidative addition (OA) of organic electrophilesto Pd(0) isa fundamental step in organopalladium chemistry and plays a key rolein palladium-catalyzed cross-coupling reactions. This perspectivesummarizes selected mechanistic studies of the Pd(0)-to-Pd(II) OAprocess involving organic halides and pseudohalides with a focus onsystems relevant to catalytic reactions. The results are organizedaccording to the nature of supporting ligands, extracting generaltrends, and describing the most relevant examples. The formation ofactive species from precatalysts is surveyed, as well as the influenceof different species that could be present under catalytic conditionsand influence the OA process, providing guidelines to facilitate theunderstanding and the improvement of catalytic reactions.