Palladium/copper-catalyzed tandem Sonogashira coupling/lactonization of methyl 2-(2′,2′-dibromovinyl)benzoate with terminal alkynes: Facile access to 3-alkynyl isocoumarins

Abstract An efficient palladium/copper-catalyzed tandem Sonogashira reaction/lactonization of methyl 2-(2′,2′-dibromovinyl)benzoate with terminal alkynes has been developed. This facile and direct approach furnishes a variety of 3-alkynyl isocoumarins in moderate to good yields under mild reaction conditions. Furthermore, this method enables concise total synthesis of natural products 3′-hydroxycorfin and gymnopalynes A.