Reduction of Vicinal Dihalides. II. Leaving Group Effects on the Electrochemical Reduction of 1,2-Dihalo-1,2-diphenylethanes and 1,2-Dihalocyclohexanes

Abstract

Leaving group effects on the electrochemical dehalogenation of organic vicinal dihalides have been examined in acetonitrile for the 1,2-dihalo-1,2-diphenylethanes and trans-1,2-dihalo-cyclohexanes. Reduction potentials and product distributions support a stepwise addition of two electrons, as previously proposed for the isomers of 1,2-dibromo-1,2-diphenylethane. A general reduction mechanism for the vicinal dihalides is proposed. Literature data for the electrochemical reduction of the 5,6-dihalodecanes, previously thought to favour a concerted two-electron mechanism, may be explained in terms of a stepwise process.