Photoredox Activation of Inert Alkyl Chlorides for the Reductive Cross‐Coupling with Aromatic Alkenes

Abstract

AbstractThe inertness of chloroalkanes has precluded them as coupling partners for cross‐coupling reactions. Herein we disclose a general strategy for the activation of inert alkyl chlorides through photoredox catalysis and their use as coupling partners with alkenes. The catalytic system is formed by [Ni(OTf)(Py2Tstacn)](OTf) (1Ni), which is responsible for the Csp3−Cl bond activation, and [Ir(NMe2bpy)(ppy)2]PF6, (PCIrNMe2), which is the photoredox catalyst. Combined experimental and theoretical studies show an in situ photogenerated NiI intermediate ([Ni(Py2Tstacn)]+) which is catalytically competent for the Csp3−Cl bond cleavage via a SN2 mechanism for primary alkyl chlorides, forming carbon‐centered free radicals, which react with the olefin leading to the formation of the Csp3−Csp3 bond. These results suggest inert alkyl chlorides can be electrophiles for developing new intermolecular strategies in which low‐valent aminopyridine nickel complexes act as key catalytic species.