Étude cinétique de l'ouverture thermique de la liaison C—C d'aziridines et d'époxydes dipôles-1,3 potentiels. II. Influence des substituants

Abstract

A kinetic study concerning the thermal opening of the C—C bond of 2-cyanoaziridines (1), 2-alkoxycarbonylaziridines (2), 2-aroyiaziridines (3), and 1,3-substituted 2,2-dicyanoepoxides (4) has shown that (i) the stereochemistry of the cyclic carbon atoms has little influence on the rate of the electrocyclic opening; (ii) the presence of an aryl substituent in position 1, as opposed to an alkyl substituent, favors this reaction and, in general, the reaction is favored by the presence of substituents which produce energy levels closer to those of the P doublet of the heteroatom and of the σ*C-2−C-3 MO. This reaction is also favored by a dissymmetry of the substitution on the 2 and 3 carbons. The results are discussed in terms of the theory of relaxations. [Journal translation]