Stereoselective Electrochemical Reduction of Imazapyr in Aqueous Media Without Chiral Auxiliaries

Abstract

The electrochemical reduction of imazapyr at the static mercury drop electrode was studied by cyclic voltammetry as a function of pH in aqueous buffered media. The process leads to the 2,3-CN double bond reduction in the imidazoline moiety in all media. The products have been isolated by controlled-potential electrolyses and identified by high performance liquid chromatography-tandem mass spectrometry measurements and 1H-NMR, 13C-NMR, and IR spectra. Although no chiral auxiliary was used, a moderate diasteroisomeric excess was observed. The diasteromeric ratio depends on pH of the electrolyses. ? 2010 The Electrochemical Society.