Recent Advances on Palladium Radical Involved Reactions

Transformations involving Pd(I) and Pd(III) have received growing attention over the past few years, providing various methodologies for the construction of numerous carbocyclic and heterocyclic ring systems. Compared with Pd(0)/(II)/(IV) chemistry, Pd(I)/(III)-mediated reactions are generally conducted through a single electron transfer process, leading to so-called palladium radical involved reactions. This review gives an up-to-date overview of catalytic methodologies involving palladium radical intermediates, which are sorted into two categories: (i) Pd(I) involved reactions and (ii) Pd(III) involved reactions. For most of these transformations, plausible mechanisms are demonstrated in detail. Clarification of these issues is the key point for understanding the palladium radical involved reactions and developing new high-performance methodologies.