The Cumulative Acceleration by Methyl Substituents on the Rate of Addition of 4-Chlorobenzenesulfenyl Chloride to Olefins

Abstract

The rate of addition of 4-chlorobenzenesulfenyl chloride to ethylene and all six of its methylated derivatives has been measured in 1,1,2,2-tetrachloroethane at 25° by means of the stopped flow and a competitive technique. A plot of log krelvs. the number of methyl groups on the carbon–carbon double bond is linear. This establishes that the methyl groups have a cumulative acceleration on the rate contrary to previous reports. The use of the competitive method of obtaining rates of arenesulfenyl chloride additions to olefins suffers from the fact that thermodynamically rather than kinetically controlled product mixtures are often formed.