A Graphite Powder Cavity Cell as an Efficient Tool of Sustainable Chemistry: Electrocatalytic Homocoupling of 2-Halopyridines

• The homocoupling of 2-halopyridines was carried out in cavity cell.
• Nickel complex was used as catalyst in the electrochemical procedure.
• Graphite powder/carbon nanotube was used as reactional cathodic medium.
• Excellent homocoupling product yields were observed using a much reduced amount of solvent (DMF).
• The cathode material proved to be recyclable with possible reuse three times without loss of activity.

A new electrochemical synthetic method for the transition metal-catalyzed homocoupling of 2-halopyridinic compounds into symmetrical 2,2’-bipyridines is described. Experiments were carried out in a cavity cell under various reaction conditions, using a nickel complex as catalyst, and controlled-potential or constant-current electrolyses. A graphite powder/carbon nanotube 9:1 ratio mixture proved to constitute the optimal cathode material. Excellent homocoupling product yields were observed using aqueous KCl solution as anolyte. The cathode material proved to be recyclable with possible reuse three times without notable loss of activity.

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