Chiral Discrimination in Electrocatalytic Oxidation of (R)- and (S)-1-Phenylethanol Usinga Chiral Nitroxyl Radical as Catalyst

Abstract

A chiral nitroxyl radical, (6R, 7S, 10R)-4-oxo-2, 2, 7-trimethyl-10-isopropyl-1-azaspiro[5.5]undecane-N-oxyl, was used as catalyst in the electrooxidation reaction of (R)- and (S)-1-phenyl-ethanol. Cyclic voltammetric studies showed that the catalytic current for the oxidation of (R)-1-phenylethanol is highly enhanced as compared with a very small enhancement in the oxidation current for the (S)-isomer. The (R)-isomer can be detected selectively in a mixture of (R)- and (S)-1-phenylethanol, even in the presence of an excess amount of (S)-isomer.