Construction of Spirocyclic Compounds via Electrochemical Intramolecular Dearomatization of Benzene Derivatives

Abstract

The spirocyclic framework is found in many natural products, some of which are biologically active. However, It remains a challenge to develop environmentally friendly and atom‐economic synthetic methods. Herein, we report an intramolecular dearomatization reaction of benzene derivatives enabled by electrochemistry‐mediated two successive single‐electron‐transfer (SET) processes, providing an alternative method for the rapid construction of spirocyclic skeletons without using sacrificial reagents. A series of cyclohexadiene products were obtained in 25‐81% yields. Furthermore, a proposed mechanism involving a sequential electron transfer event was supported by cyclic voltammetry experiments. This strategy features transition‐metal‐free conditions and easy handling, which will greatly enhance its practical utility.