Oxime palladacycles revisited: stone-stable complexes nonetheless very active catalysts

Our review critically presents the main achievements, advantages, and limitations of oxime palladacycles as high-turnover catalysts for Heck, as well as homo- and cross-coupling reactions such as Suzuki-Miyaura, Stille, Ullmann-type, Cassar-Heck-Sonogashira, sila-Sonogashira, Glaser-type, Hiyama, and alkoxycarbonylation reactions. New developments in this area are reviewed from a mechanistic and synthetic point of view. The role of oxime palladacycles as a source of highly active zero-valent palladium species is also discussed.