Aqueous 30% H2O2 in hexafluoro-2-propanol (I-IFIP) is described as a facile, selective and efficient oxidative system for the conversion of l-trifluoromethyl vinyl sulfides to the corresponding vinyl sulfoxides under neutral conditions. By using 3-chlorobenzoic acid or other oxidizing reagents, further oxidation into vinyl sulfones was observed. (C) 1999 Elsevier Science S.A. All rights reserved.
Short and efficient preparation of trifluoromethyl vinyl sulphides
S-Alkyl trifluorothioacetate 2 reacts with stabilized and non-stabilized phosphoranes 1 to afford a new and general route to a wide range of trifluoromethyl vinyl sulphides 3. Until now, no general methods allowed the preparation of these interesting compounds.
At low temperatures, perfluoro-cis-2,3-dialkyloxaziridines 4 oxidize 1-trifluoromethylvinyl sulfides 1 to the corresponding sulfoxides 2 in quantitative yields. By using 3-chloroperoxybenzoic acid, or the same oxaziridines at room temperature, sulfones 3 are formed exclusively.