One-Pot Vicinal and Geminal Double Carboalkoxylation with N-Carboalkoxy-imidazole by Electroreduction of Aromatic Vinyl and Imine Derivatives

Abstract

One-pot vicinal double C-carboalkoxylation of styrene derivatives has been developed by electroreduction in the presence of a large excess of N-carboalkoxyimidazoles in N,N-dimethylformamide (DMF) containing tetra-n-butylammonium bromide as a supporting electrolyte using an undivided cell equipped with Zn-plate as the anode and cathode under the constant current conditions until 6 F/mol of electricity passed through the system, to afford the corresponding phenylsuccinic acid esters in good to moderate yields. On the other hand, electroreduction of aromatic imine derivatives under the similar conditions brought about one-pot geminal double C-carboalkoxylation, giving the corresponding aryl aminomalonic esters in moderate yields. As one of the most plausible mechanism, electron transfer to carbon-carbon and carbon-nitrogen double bonds may involved as the first step, followed by electrophilic C-carboalkoxylation.