Redox transfer. Part VIII. Addition of benzenesulphonyl chloride and carbon tetrachloride to substituted styrenes: a kinetic study

Abstract

A kinetic study of the copper chloride-catalysed addition of benzenesulphonyl chloride to a number of styrenes carrying substituents of widely different electronegativity shows that the overall rates are very little affected by the substituent. This rules out the possibility of a concerted reaction, in which the olefin should participate in the rate-determining step, and confirms a redox chain mechanism. The lack of stereospecificity of the addition of carbon tetrachloride to norbornene points to the same conclusion. β-Methylstyrene reacts much more slowly with benzenesulphonyl chloride than the other styrenes. This is attributed to an unfavourable equilibrium for sulphonyl radical addition to this olefin. Carbon tetrachloride adds at the same rate to different olefins, including β-methylstyrene, in accord with the redox chain mechanism.