Kinetic Studies on the Structure-Reactivity Correlation of Aryl N-Phenyl Thioncarbamates

Abstract

Although there is abundant literature on the kinetics and mechanism of the aminolysis of aryl carbonates and esters, the aminolysis reactions of aryl carbamates have been less studied in terms of kinetics. The mechanism of the aminolysis of substituted diphenyl carbonates has been studied, and structure-reactivity relationships for those reactions have also been examined in detail by Gresser and Jencks. Castro and co-workers have reported a number of mechanistic studies on the aminolysis of aryl carbonates and esters. These and other studies showed that most of the aminolysis of aryl carbonates and esters proceed by either a stepwise mechanism through a zwitterionic tetrahedral intermediate, T, or a concert mechanism depending on the amine, substrate, and solvent involved. Aryl esters, 1, carbonates, 2, and carbamates, 3, are three classes of compounds which differ only in the acyl part, R,