Facile Method for the Preparation of Triarylsulfonium Bromides Using Grignard Reagents and Chlorotrimethylsilane as an Activator

Triarylsulfonium bromides were synthesized by the reaction of diaryl sulfoxides with aryl Grignard reagents in the presence of TMSCI followed by treatment with HBr aqueous solution. Triarylsulfonium bromides bearing threeidentical substituents on sulfur atom were synthesized by the treatment of dimethyl sulfite or thionyl chloride with 5 equivalents of Grignard reagent in the presence of TMSCI.