Metal carbonyls, electroreduction

The complex [Ni(bpy)2]2+ catalyzes the electroreductive coupling of organic halides and carbon monoxide into ketones under a CO atmosphere,226 or in the presence of a metal carbonyl,227 especially iron pentacarbonyl. Unsymmetrical ketones have been obtained from mixtures of two different organic halides.228 CO is very reactive towards reduced Ni° species to form the stable [Ni°(bpy)(CO)2]° complex, which probably evolves to a transient arylnickel [Nin(bpy)(R)(CO)X]° complex in the presence of both ArX and [Ni°(bpy)]° species.229,230... 

Indirect electrosynthesis of reactive formyl transition metal compounds involves an initial step of reduction of metal carbonyls to radicals followed by transfer of a hydrogen atom from trialkyltin hydrides190. Electroreduction of metal carbonyls yields products of dimerization and loss of CO from the radical anion. Electroreduction in the presence of R3SnH yields the formylmetalcarbonyls ... 

The electroreductive carbonylation and carboxylation of organic halides catalyzed by different metal complexes is summarized in Section 9.10.5. Electrogenerated Ni° complexes containing bpy193-196 or pentamethyldiethylenetriamine196-199 ligands are effective catalysts for the electrosynthesis of... 

The electroreduction of the carbonyl group in aqueous or partially aqueous electrolytes primarily yields the corresponding alcohol and alkane, metal alkyl compounds, and a 1,2-diol ... 

---