Electrochemical Reduction of Ethyl 2-(2-(Bromomethyl)Phenoxy)Acetate at Carbon Cathodes in DMF Affected By the Presence of Oxygen

摘要

Many cyclic and bicyclic compounds have been synthesized by electrochemical means via direct reduction of various organic halides involving carbanion intermediates. For example, electrochemical cyclization of allylic α,ω-dibromides was accomplished for the synthesis of cycloalkadienes while reduction of dimethyl α,α'-dibromoalkanedioates at platinum cathodes in DMF could produce dimethyl 1,2-cylcoalkanedicarboxylates in relatively high yields. More interestingly, electrolyses of o-trichloroacetylanilides in acetonitrile at selected cathodic potentials would lead to different bicyclic products, depending upon the substituents on the imine group. Recently, our group studied the reduction of methyl 2-bromomethylbenzoate at carbon cathodes in DMF and found that the corresponding benzylic anions could be formed, which would undergo intramolecular cyclization in the presence of water to generate phthalide. Nevertheless, electrochemical methods are limited for the synthesis of heterocyclic compounds by direct reduction of organic halides, mostly due to the low product yields. Some haloalkenes can also be reduced to radicals to form different cyclic compounds. However, these processes often require various metal catalysts.