Views: 23 Author: Site Editor Publish Time: 2018-10-12 Origin: Site
The electroreduction reaction of methyl cinnamate on a boron-doped diamond (BDD) electrode was investigated. The hydrodimer, dimethyl 3,4-diphenylhexanedioate (racemate/meso = 74:26), was obtained in 85% yield as the major product, along with small amounts of cyclic methyl 5-oxo-2,3-diphenylcyclopentane-1-carboxylate. Two new neolignan-type products were synthesized from the hydrodimer.
Numerous lignans and neolignans were found as secondary plant metabolites, and many of them are known to exhibit interesting biological activities . Due to their plausible roles as defense substances of plants, lignans, neolignans, and their congeners are promising candidates for agricultural chemicals, and some of their antioxidant and/or anti-inflammatory properties may be utilized for biological research and as lead structures for chemotherapeutic agents. Despite consisting of two phenylpropane (C6–C3) fragments, the variety of carbon frameworks provides a huge library of lignans and neolignans [2-4].
As a result of their structural diversity, they have been targets of synthetic and biological investigations. Several synthetic approaches, including electrochemical oxidative coupling reactions mimicking biosynthetic pathways, were reported to construct the backbones of these molecules . Recently, boron-doped diamond (BDD) electrodes have attracted a great deal of attention for their wide potential window against evolution of both hydrogen and oxygen and for their high stability which is derived from their diamond carbon structure .
Although anodic oxidation reactions mediated by BDD electrodes have been exploited in organic synthesis, there have been only few reports regarding their application in preparative-scale cathodic reduction of organic compounds