Stereodivergent formation of fluorine-containing enamides

2-Chloro-1,1,1,2-tetrafluoroethane 1 (HCFC-124) obtained as one of the major byproducts of tetrafluoroethylene synthesis were successfully employed for the stereodivergent construction of tetrafluorinated enamides 4 just by selection of a base for affecting the removal of HCl.

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► Convenient reaction of HCFC-124 with aromatic imines protected by Boc or Ts groups on nitrogen.
► Smooth conversion of aromatic groups in the above products to the methyl ester in two steps.
► Stereodivergent construction of fluorinated enamides just by selection of a base.