FACTORS INFLUENCING EPISULFONIUM ION FORMATION . REACTIVITY OF UNSATURATED ALIPHATIC HYDROCARBONS TOWARD METHANESULFENYL CHLORIDE

The reaction of methanesulfenyl chloride with a series of unsaturated hydrocarbons has been utilized to measure relative rates of episulfonium ion formation. The structure-reactivity correlation obtained in this fashion contrasts with other electrophilic additions such as chlorination in that the methanesulfenyl chloride additions appear to be significantly less sensitive to the nucleophilicity of the unsaturated hydrocarbon and quite sensitive to steric factors. The data have been interpreted in terms of transition states in which the positive charge resides essentially on sulfur, and consequently alkyl substituents about the double bond contribute relatively little toward delocalization of the positive charge. The observed reactivities reflect the opposing steric and electronic factors. © 1969, American Chemical Society. All rights reserved.