Pummerer-Type Reaction of a-Acylsulfides Using Phenyl Iodosyl Bis(trifluoroacetate)

Treatment of a-acylsulfides with phenyl iodosyl bis(trifluoroacetate) (PIFA) resulted in a Pummerer-type reaction to give the same products as obtained by the Pummerer reaction of the α-acylsulfoxides. The Pummerer-type reaction of a-acylsulfides using PIFA was applied to Friedel-Crafts type cyclization of N-phenyl-α-(methylthio)acetanilide (1) and ethyl α-(l-phenethylthio)-acetate (9) to give N-phenyl-3-(methylthio)oxindole (3) and ethyl isothiochroman-l-carboxylate (10), respectively, olefin cyclization of a-(methylthio)acetamides (11, 13 and 15) to give the lactams (12, 14 and 16), and also intermolecular condensation and a-methoxylation of methyl α-(methvlthio)acetate (7).