Reductive elimination of chlorinated ethylenes by zero-valent metals

To date it does not appear to have been demonstrated in the literature that halogenated ethylenes can undergo reductive β-elimination to alkynes under environmental conditions. The purpose of this paper is to provide experimental evidence that such pathways may be involved in the reaction of chloroethylenes with zero-valent metals as well as to speculate on the significance of the products that may result. Calculations indicate that reductive β-elimination reactions of chloroethylenes are in fact comparable energetically to hydrogenolysis at neutral pH. Experiments were therefore initiated to assess whether β-elimination reactions of chlorinated ethylenes could occur in the presence of two zero-valent metals, Fe and Zn.