HFC-134a as a fluorinated building block: short syntheses of α-fluoroenones

1,1,1,2-Tetrafluoroethane (HFC-134a) has been transformed into a range of α-fluoroenones via a direct route. Dehydrofluorination/metallation allowed trifluorovinylsilanes to be prepared; these could be converted in situ, or isolated and treated further, with alkyllithium reagents to give difluorovinylsilanes. Fluoride-catalysed addition to aldehydes followed by acidic work-up allowed the isolation of a range of α-fluoroenones in two- or three-pots.