Recent Advances in Radical-Enabled Bicyclization and Annulation/1,n-Bifunctionalization Reactions

Over the past few years, the development of new radical reactions has gained considerable momentum. Most such radical transformations heavily depend on the in situ generation of reactive radical species, initiated by oxidants, metal salts, visible-light photocatalysis, or electrocatalysis. In this context, numerous radical-enabled bicyclization and annulation/1,n-bifunctionalization reactions have been developed, thereby providing efficient synthetic strategies for the assembly of functionalized cyclic rings that contain both heterocyclic and isocyclic skeletons. In this Focus Review, we highlight recent progress in this rapidly growing area by presenting a series of catalytic oxidative reactions, along with their reaction mechanisms and applications.