l-Proline catalyzed condensation–cyclization tandem process: Facile and effective synthesis of 3-polyfluoroalkanesulfonyl coumarin

A l-proline catalyzed condensation–cyclization tandem process is reported, which affords the potentially pharmaceutic coumarin derivatives. The mild conditions, simplicity of the purification process and satisfactory yields makes the method a facile and effective way toward the 3-polyfluoroalkanesulfonyl coumarins.