Room temperature nickel (0)-catalyzed Suzuki-Miyaura cross-couplings of activated alkenyl tosylates:: Efficient synthesis of 4-substituted coumarins and 4-substituted 2(5H)-furanones

Room temperature nickel(0)/tricyclohexylphosphine [Ni(0)/PCy3]-catalyzed Suzuki-Miyaura cross-couplings of 4-(p-toluenesulfonyloxy)coumarins and 4-(p-toluenesulfonyloxy)-2(5H)-furanone with arylboronic acids are described in this communcation. Our study shows that activated alkenyl tosylates possess higher activities than aryl tosylates in the Suzuki-Miyaura cross-couplings. The mild reaction conditions and the high efficiency of the Ni(0)/ PCy3 catalyst make it very useful in the synthesis of 4-substituted coumarins and 4-substituted 2(5H)-furanones, two families of biologically important molecules.