Jean-Louis Clavel

A NEW CONVENIENT AND INEXPENSIVE METHOD FOR PREPARATION OF ALKYL- ARYLTRIFLUOROMETHYL SULFIDES IN REDUCTIVE MEDIUM

Abstract A new convenient and general method for preparation of alkyl or aryltrifluoromethyl sulfides is described.

Trifluoromethylation with sodium trifluoromethanesulfinate under oxidative conditions

Abstract Trifluoromethyl radicals ·CF3 can be generated by monoelectronic oxidation (for instance with tertiobutyl hydroperoxide) of sodium trifluoromethanesulfinate (CF3SO2Na). This useful and cheap precursor of triflic acid results from bromotrifluoromethane and sulfur dioxide radical-anion (1). Under these conditions, CF3SO2Na is able to convert mildly organic disulfides into tri-fluoromethyl thioethers (2) and to trifluoromethylate enol esters. In the latter case, additional catalytic amounts of cupric salts are necessary to oxidize the intermediate radical, in order to prevent the formation of by-products. The reaction can be thus considered as a formal electrophilic trifluoromethylation. Aromatic trifluoromethylation can be also performed with the same system and the ratio between mono and his trifluoromethylated products is dependent upon the presence or absence of catalytic cupric salts.

Synthesis of perfluoroalkylthioethers from disulfides

Abstract Perfluoroalkylthioethers are synthesized from disulfides and freons, halons or halogenoperfluoroalkanes according to: 2R F X + 2Red+ RSSR → 2R F SR + 20x This reaction was studied with aliphatic, aromatic and heteroaromatic disulfides Several reductor systems have been used. They behaved as sulfur dioxide-radical anion precursors. The initial step is interpreted by single electron transfer from this radical anion to the halide. The mechanism will be discussed. Halogenoalkylthioethers groups are very lipophilic and interesting as substituents for pharmaceutical drugs and agrochemical compounds.