Methyl-Transfer Reactions. 7. System with CH3OSO(1+) Intermediate

Article abstract of DOI:10.1021/jo00163a021

Methyl chlorosulfite with antimony pentachloride in thionyl chloride initially at dry ice temperature is a very powerful methylating system.It methylates sulfones, methyl chloride, and even to some extent dimethyl sulfate.The active methylating species is apparently the cation CH3OSO(1+).Dimethyl sulfite is decomposed catalytically by methyl trifluoromethanesulfonate to dimethyl ether and sulfur dioxide, and the same cation appears to be intermediate.The mechanism includes an exchange of the methyl groups between the two esters, allowing a practical synthesis of methyl -d3 triflate.Dimethyl sulfite does not methylate detectably on sulfur.