Photoinduced Cobalt-Catalyzed Alkyl Radical-Initiated Polarity Cross-Coupling Cyclization of Unactivated Olefins to Access Saturated Heterocycles

Abstract

High-valent alkylcobalt catalysts hold great potential in streamlining synthetic routes to access broad classes of synthetic targets from feedstock alkenes. Notably, exploiting a new reaction mode by circumventing the overwhelming cobalt-mediated hydrogen atom transfer would remarkably extend the chemical space of orthogonality-driven functionalization of alkenes. We herein report a cobalt/photocatalytic carboheterocyclization of unactivated olefins through orchestrating radical addition/intramolecular radical polarity cross-coupling nucleophilic cyclization. This protocol provides a straightforward route to rapidly assemble a series of saturated heterocycles, such as tetrahydrofuran, tetrahydropyran, tetrahydropyrrole, and piperidine. The designed binary system successfully synchronized the photoinduced radical-involved reaction events with cobalt-mediated polar cross-coupling via high-valent alkylcobalt catalytic species.