Enantioselective Catalytic Oxidation of 1-Phenylethanol on a Chiral Nitroxyl Radical-terminated Self-assembled Monolayer Modified Electrode

Abstract

Thiol derivatized (6S,7R,10R)-4-amino-2,2, 7-trimethyl-10-isopropyl-1-azaspiro [5.5J undecane-1-yloxyl was synthesized to modify the surface of a gold electrode with its self-assembled monolayer. This modified electrode showed symmetrical reversible redox wave at +0.62 V vs. Ag / AgCl, which originates from the electron transfer between the self-assembled monolayer and electrode. The modified electrode exhibited an enantioselective catalytic oxidation for chiral secondary alcohols ; (S)-(−)-1-phenylethanol was oxidized into the ketone more efficiently than (R)-(+)-l-phenylethanol.