Diels–Alder reactions of “in situ” generated perfluorinated thioketones

A simple and general procedure for the preparation of Diels–Alder adducts of perfluorinated thioketones and various dienes is reported. The corresponding Diels–Alder adducts were prepared in 30–78% yield under mild conditions via a reaction of a mixture of fluoroolefins, sulfur, diene and CsF as a catalyst.