Studies on sulfinatodehalogenation. Part 30. Synthesis of 3-perfluoroalkylated coumarins, thiocoumarins and 2-quinolones by direct perfluoroalkylation with perfluoroalkyl iodides and sodium hydroxymethanesulfinate

Abstract

Coumarins react with perfluoroalkyl iodides in the presence of sodium hydroxymethanesulfinate (Rongalite) to give 3-perfluoroalkylcoumarins selectively in good yields and under mild conditions. The same results were obtained when thiocoumarin and 2-quinolones were used in place of coumarins and the corresponding C-3 substituted perfluoroalkyl thiocoumarins and 2-quinolones were prepared readily. A free-radical mechanism was proposed for the reaction.