Palladium(II)-Catalyzed Carbonylations

Palladium(II) species are able to promote a large variety of carbonylation reactions. Generally speaking, Pd(II) is more electrophilic than Pd(0), so it is able to electrophilically attack different organic substrates, including alkanes, aromatic rings, carbon–carbon multiple bonds, alcohols, phenols, and amines. The resulting organopalladium intermediates can then insert carbon monoxide by migratory insertion with formation of organocarbonylpalladium species. These then evolve toward the final carbonylated compound(s), whose particular structure depends on the nature of the organic substrate and reactions conditions. In many cases, at the end of the carbonylation process, palladium(II) is reduced to palladium(0), so the presence of a suitable oxidizing agent is necessary to achieve a catalytic cycle (oxidative carbonylation). In this chapter, the most important Pd(II)-catalyzed carbonylation processes are presented and discussed.