Disclosing Cyclic(Alkyl)(Amino)Carbenes as One‐Electron Reductants: Synthesis of Acyclic(Amino)(Aryl)Carbene‐Based Kekulé Diradicaloids

Herein, we disclose cyclic(alkyl)(amino)carbenes (CAACs) to be one‐electron reductants under the formation of a transient radical cation as indicated by EPR spectroscopy. The disclosed CAAC reducing reactivity was used to synthesize acyclic(amino)(aryl)carbene‐based Thiele and Chichibabin hydrocarbons, a new class of Kekulé diradicaloids. The results demonstrate CAACs to be potent organic reductants. Notably, the acyclic(amino)(aryl)carbene‐based Chichibabin's hydrocarbon shows an appreciable population of the triplet state at room temperature, as evidenced by both variable‐temperature NMR and EPR spectroscopy.