Catalytic reduction of ethyl chloroacetate by cobalt(I) salophen electrogenerated at vitreous carbon cathodes

Cyclic voltammetry, controlled-potential electrolysis, and electrospray ionization–mass spectrometry have been employed to investigate and characterize the catalytic reduction of ethyl chloroacetate (ECA) by cobalt(I) salophen, [Co(I)L]−, electrogenerated at a carbon cathode in dimethylformamide containing tetramethylammonium tetrafluoroborate. For the catalytic reduction of ECA by [Co(I)L]−, which proceeds via an ethoxycarbonylmethylcobalt(III) salophen complex, [RCo(III)L], the principal products are ethyl acetate, ethanol, and 1,2,3-cyclopropane tricarboxylic acid triethyl ester. In addition, we have found that, during the catalytic reduction of ECA by [Co(I)L]−, a new cobalt(I) species, [Co(I)LR]2−, can be formed which is catalytically active toward ECA and which has an ethoxycarbonylmethyl moiety bound to the imino carbon atom of the salophen ligand.