Substitution effects on the aza-di-π-methane rearrangement of imines

Abstract

The u.v. irradiation of several 1-aryl derivatives of 3,3-dimethyl-5,5-diphenyl-1-azapenta-1,4-diene has been carried out. All of them undergo the aza-di-π-methane rearrangement and yield a cyclopropylimine. The influence of substituents on the 1-aryl group has given support for the proposal that imines with a low ionization potential are less efficient at undergoing the aza-di-π-methane process than are imines with a higher ionization potential. This was demonstrated in a quantitative fashion. The involvement of an electron-transfer process in the reaction is discussed.