Stable Ambiphilic Bis(N‐Heterocyclic Imino)‐Substituted Terminal Olefin and Its Diazoolefin Derivative Exhibits Unusual Dimerization

In this article, we report a novel bis(N-heterocyclic imino) terminal olefin, [{(CAAC)N}₂C═CH₂] [CAAC = cyclic (alkyl)(amino)carbene], which exhibits reactivity distinct from traditional N-heterocyclic olefins. The use of the (CAAC)-derived ambiphilic N-heterocyclic imino fragment {(CAAC)N‒} was crucial in imparting the unique properties of [{(CAAC)N}₂C═CH₂]. The imino groups act as strong electron donors, rendering the terminal olefin polar through π-delocalization, whereas the carbenic carbon of CAAC introduces an electrophilic site into the imino substituent. This combination results in an inherently ambiphilic olefin that displays unusual reactivity. Specifically, the reaction of [{(CAAC)N}₂C═CH₂] with tosyl azide, under varying stoichiometric conditions, furnished four distinct nitrogen-rich compounds, including two unprecedented nitrogen-containing heterocycles. Quantum-chemical calculations were carried out to elucidate the bonding features of the ambiphilic bis-imino terminal olefin as well as the newly formed heterocycles.