Optimization and Mechanistic Studies of the Electrochemical Dimerization of Primary Alkyl‐Bromides and Benzylic Chlorides Utilizing a Nickel(II)/Terpyridine Catalytic System

Electrochemical reductive homo‐coupling of alkyl halides provides a sustainable alternative to metal‐powder‐based protocols. We report a nickel‐catalyzed system operating under mild electroreductive conditions that delivers C(sp 3 )–C(sp 3 ) dimers efficiently using either a sacrificial anode or a metal‐free graphite/DIPEA setup. Various Ni(II) precursors combined with terpyridine ligand proved effective, enabling the dimerization of a range of primary alkyl halides and benzylic substrates. Electrochemical analysis highlights the role of the initial reduction of the Ni(II) precatalyst and reveals a strong influence of the counter‐anion on nickel speciation. In particular, lithium halides enhance reactivity by altering the coordination environment of nickel. These findings establish a practical and tunable platform for electrochemical dimerization and clarify how ligand and salt effects govern catalytic efficiency.