N-Heterocyclic Selone-Generated Selenium-Centered Radical for Covalent Radical Catalysis

Abstract Covalent radical catalysis represents an emerging synthetic paradigm that exploits open-shell radical species as catalysts to drive chemical transformations. By enabling selective manipulation of highly reactive radical intermediates via controlled addition–elimination sequences, this approach offers a mild and versatile route for constructing complex cyclic frameworks with high efficiency and precision. This highlight article briefly summarizes recent advances in this area, with emphasis on our development of redox-active N-heterocyclic selones (NHSs) as catalysts. These catalysts facilitate a radical-catalyzed [2σ + 2π] cycloaddition platform, providing direct access to 1,3-bicyclohexanes—geometrically congruent bioisosteres of meta-substituted benzene.