Novel and selective palladium-catalyzed annulations of 2-alkynylphenols to form 2-substituted 3-halobenzo[b]furans

[GRAPHICS] A novel and selective palladium-catalyzed annulation of 2-alkynylphenols method for the synthesis of 2-substituted 3-halobenzo[b]furans is presented. In the presence of PdX2, CuX2, and HEt3NX, 2-substituted 3-halobenzo[b]furans were selectively obtained as the major products. The mechanism of the reaction was also discussed.