Thirteen difluoromethyl-containing pseudopeptides were synthesized by Ugi reaction using the novel building block 2,2-difluoro-2-(phenylthio)acetic acid (2) as one component, followed by removal of the phenylsulfanyl protecting group in the presence of tributyltin hydride and azobisisobutyronitrile.
Keywords: Ugi reaction; difluoromethyl functionality; gem-difluoromethylene-containing acid; pseudopeptides; reductive cleavage.