Rapid progress in palladium-catalyzed reactions: Novel palladium-catalyzed reactions recently discovered

New palladium-catalyzed reactions recently discovered which involve P-carbon elimination and formation of palladacycles as key reactions are surveyed. Arylation of aromatic ring takes place by the reaction of alpha, alpha-disubstituted arylmethanols with aryl halides via beta-carbon elimination. Novel methods of functionalization of aromatics were discovered by Catellani by the unique palladium and norbornene-catalyzed coupling reactions of aryl halides. Polyarylations of phenols and other aromatic rings with aryl halides proceed smoothly via facile formation of palladacycles due to the participation of OH groups. These reactions proceed via the following interconversion between Pd(0)-Pd(II)-Pd(IV) species.