From Stoichiometry to Catalysis: Electroreductive Coupling of Alkynes and Carbon Dioxide with Nickel-Bipyridine Complexes. Magnesium Ions as the Key for Catalysis

Article abstract of DOI:10.1021/ja00022a037

The incorporation of carbon dioxide into nonactivated alkynes catalyzed by electrogenerated nickel-bipyridine complexes affords α,β-unsaturated acids in moderate to good yields.The electrocarboxylation reaction was undertaken on a preparative scale in the presence of a sacrificial magnesium anode: the formation of acids from alkynes is stoichiometric with respect to the nickel complex if performed in a two-compartment cell but can be made catalytic in a single-compartment cell.An intermediate nickelacycle was isolated from the reaction with 4-octyne.The cleavage ofthis metallacycle by magnesium ions is the key step to explain catalysis.