Palladium Catalyzed Transformation of Acyclic Units to Furans

Pd-catalyzed furan ring formation processes involving acyclic units are reviewed. A number of methods, which allow the construction of wide variety of functionalised furan rings from acetylenic building blocks such asalkynones, alkynols, epoxyalkynes, and o-alkynyl phenols have been described. Alkynes containing proximate oxygen nucleophile in the presence of palladium complexes undergo cyclization to form furans via formation of new oxygen-carbon bond. Tandem cyclization reactions have been utilized for the construction of a wide variety of functionalised furans rings and providing important new dimensions in the design of synthetic strategies.