Photoredox Activation of Inert Alkyl Chlorides for the Reductive Cross‐Coupling with Aromatic Alkenes
Jordi Aragón, Suyun Sun, David Pascual, Sebastian Jaworski, Julio Lloret‐Fillol
Abstract
Abstract The 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)(Py 2 Ts tacn)](OTf) ( 1 Ni ), which is responsible for the Csp 3 −Cl bond activation, and [Ir( NMe2 bpy)(ppy) 2 ]PF 6, ( PC Ir NMe2 ), which is the photoredox catalyst. Combined experimental and theoretical studies show an in situ photogenerated Ni I intermediate ([Ni(Py 2 Ts tacn)] + ) which is catalytically competent for the Csp 3 −Cl bond cleavage via a S N 2 mechanism for primary alkyl chlorides, forming carbon‐centered free radicals, which react with the olefin leading to the formation of the Csp 3 −Csp 3 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.