Theoretical study of NH and CH acidities of toluidine isomers – dependence on their oxidation states

Abstract

For the toluidine isomers, the amino group acidity represents a characteristic feature of these compounds in their electric neutral state. The CH acidity of methyl group is hidden under NH acidity. As demonstrated by theoretical calculations based on the quantum chemistry composite method G4 and Density functional theory, the transformation of toluidines into their mono- and bi-oxidised states significantly increases the acidity of methyl group. This study indicates that the presence or absence of these deprotonated species in reaction mixture will determine the CN or CC coupling toluidine products