Alkyl‐ and Aryl‐Thiolation.: A kinetic study with bis‐phenylsulfonylmethane

Abstract

The kinetics of the reaction of bis‐phenylsulfonylmethane with thiosulfonic esters (RSSO2R′) have been measured in 100% ethanol, in the presence of triethylamine, at 20°. The kinetic data on the substitution of an ‘active’ hydrogen by a thioaryl or thioalkyl (RS) group are compatible with a two‐step mechanism. First the carbanion of bis‐phenylsulfonylmethane is formed by action of the base after which a bimolecular reaction occurs between the carbanion and the thiosulfonate. The reaction is retarded by introduction of electrondonating substituents in both R and R′. The possible structure of the transition state is discussed.