Selectivity and the Ritchie equation

Abstract

The rates of addition of six primary amines to various electrophiles in aqueous solution have been analysed using a log k–log k type LFER treatment. Observed behaviour is in accord with the reactivity–selectivity principle and in quantitative agreement with previous work, questioning the validity of the Ritchie equation over large ranges of Lewis acidity. It is suggested that it is the range of electrophile stability considered, and not the intrinsic reactivity of the electrophiles themselves, which determines the degree of conformity to Ritchie type constant selectivity relationships.