A NEW ROUTE FOR THE PREPARATION OF SUBSTITUTED 2,2-DIFLUOROSTYRENES AND A CONVENIENT ROUTE TO SUBSTITUTED (2,2,2-TRIFLUOROETHYL)BENZENES

The (2,2-difluoroethenyl)zinc reagent II is coupled with aryl iodides or bromides in the presence of Pd(PPh3)(4) in DMF to give the correspo nding 2,2-difluorostyrenes IV. The 4-substituted (tetrafluoroaryl)copp er reagents are coupled with 2,2-difluoro-1-iodoethylene (I) to produc e the corresponding styrene derivatives VII. Both methods provide good yields of the coupled products. These products react with wet KF in D MF or DMSO to form the (2,2,2-trifluoroethyl)benzene derivatives VIII in good yields.