Trifluoromethanesulphonyl chloride

In a mechanistically related process, Fukamiya, Okano and Aratani have shown38 that the reaction of a sulphoxide with 3 mole equivalents of trifluoromethanesulphonyl chloride and iodine in cold, dry THF gives the corresponding sulphide in yields ranging from 52 to 96%. When compared to t-butyl bromide, this reagent is more expensive, and the products were isolated after chromatographic separation. The reaction pathway can most probably be described as depicted in equation (14) ... 

It was concluded, from the establishment of a crude p-value of -1-0.46 for the reaction, that the process may involve [CT 3CuI] as an intermediate. A similar process may be involved in the reaction of trifluoromethanesulphonyl chloride with copper (Figure 10.59). 

Trifluoromethanesulphonyl chloride efficiently dichlorinates malonic esters and related compounds with similarly acidic protons. ... 

Disubstituted tetrahydrofurans are available from the reaction of dialkyl hydroxyalkylmalonates with trifluoromethanesulphonyl chloride (Scheme 27), ... 

Sulphonamides.— Oxidative amidation of sulphinic acids gives primary sulphon-amides, though the severe reaction conditions (18% oleum with NaNj) restrict the potential of this route. Selective amino sulphonation of anilines, using CISOjNCO and AlClj, depends on the formation of cyclic A-carbamoyl-sulphonamides. More conventional preparative methods are covered in the conversion of naphthalene-1-thiol into 4-(2-hydroxyethylsulphonyl)naphthalene-1-sulphonamide (an assessment of standard routes has been made), and in the preparation of alkanesulphonyl- and trifluoromethanesulphonyl-hydroxyl-amines from hydroxylamines and the sulphonyl chlorides. In the latter study,conditions favouring N- rather than 0-sulphonylation were established. 

---