An Unexpected Addition of Acetic Acid to ortho-Electron-Deficient Alkynyl-Substituted Aryl Aldehydes Catalyzed by Palladium(II) Acetate

An unexpected addition of acetic acid to ortho-electron-deficient alkynyl-substituted aryl aldehydes catalyzed by palladium(II) acetate was achieved, which provided a convenient method for the synthesis of dihydroisobenzofurans in moderate to good yields. The electron-withdrawing groups attached to alkynes may play an important role for the cyclization.