Metal-catalyzed synthetic strategies toward coumarin derivatives

Modern approaches toward coumarin ring construction based on metal-catalyzed reactions significantly complement and extend the applicability of classical methods by increasing the reaction rates and product yields. The present review summarizes various approaches to the synthesis of coumarin derivatives catalyzed by different metals – palladium, gold, copper, silver, platinum, iron, cobalt, rhodium, gallium, nickel, and zinc. Among these, palladium-catalyzed reactions are the most numerous and significant in many aspects. The review covers literature over the last 20 years.