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} 2 C═CH 2 ] [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} 2 C═CH 2 ]. 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} 2 C═CH 2 ] 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.