The effect of lateral chains on the electrochemical and physico-chemical behaviour of Tosyl-N-protected aminoacids

The electrochemical behaviour in protic and aprotic solvents of some tosylaminoacids bearing a lateral electroinactive chain confirms that the reduction mechanism conforms to that one already proposed for tosyl- and dansylglycine and benzenesulphonamide derivatives. The E value reveals to be a good structural index and relationships between empirical and calculated structural parameters show that the presence of the carboxylate group in tosylaminoacids causes an increase of NH bond acidity with respect to benzenesulphonamide derivatives. The pK values of the amide group are influenced by the kind of the lateral chains and by the position of carboxylic group in the molecular frame.