Electrochemical reduction of diheteroaryl-1,2-diketones in the presence of carbonimidoyl dichlorides. First synthesis of 2-arylimino-4,5-di-2-furyl-1,3-dioxoles and (E)-1,2-di-2-furylvinylene bis(N-arylchloroformimidates)

Selective cathodic reductions of 2,2′-furil in an aprotic medium, under constant potential, in the presence of equimolecular amounts of N-arylcarbonimidoyl dichlorides provide previously unknown 2-arylimino-4,5-di-2-furyl-1,3-dioxoles in high yields. These compounds were formed accompanied by minor products which were identified as (E)-1,2-di-2-furylvinylene bis(N-arylchloroformimidates), a new class of compound. Similar reductions were applied to 2,2′-pyridil, 2,2′-thenil and bis(pyrrol-2-yl)-1,2-ethanedione. However, arylisocyanides were quantitatively generated by mediated electroreduction of arylcarbonimidoyl dichlorides.