Abstract

In this study, we attempted to explain why the substitution of a cyano group onto the 1-azadiene moiety promotes N-(2,3-diphenylallylidene)pent-4-en-1-amine to undergo an intramolecular aza-Diels–Alder reaction. Our M06-2X study found that the intramolecular aza-Diels–Alder reaction of N-(2,3-diphenylallylidene)pent-4-en-1-amine has an inverse electron demand. Therefore, the attachment of a cyano group to the diene moiety (1-azadiene) makes the intramolecular aza-Diels–Alder reaction feasible. Moreover, the intramolecular aza-Diels–Alder reaction of N-(2,3-diphenylallylidene)pent-4-en-1-amine was found to be a kinetically controlled reaction. © 2022 John Wiley & Sons Ltd.