LINEAR FREE-ENERGY RELATIONSHIP STUDIES OF THE DIMETHYLDIOXIRANE C-H BOND INSERTION REACTION

The relative rates of reaction of a series of p-substituted cumenes wi th dimethyldioxrane have been studied. The products are the correspond ing cumyl alcohols. Treatment of the rate data with the Hammett substi tuent constants reveals that the insertion reaction is an electrophili c process with rho = -2.76. Similar treatment of the data with the Bro wn-Okamoto substituent constants gives rho(+) = -1.61. The second-orde r rate constants for the reaction of a series of substituted adamantan es with dimethyldioxirane were also determined. Again, the products ar e the corresponding adamantanols. The rate constants were correlated w ith several types of substituent constants. The best correlations were obtained with the Taft sigma() and sigma(I) constants which gave rho () = -1.08 and rho(I) -2.39, respectively. Thus, the insertion reacti on in this aliphatic system is also electrophilic.