Enantioselective Hydrogenations on Platinum Colloids

Abstract

The chemical reduction of aqueous solutions of platinum salts in the presence of the alkaloid dihydrocinchonidine yields chirally coated platinum colloids. The particle sizes can be varied in a controlled fashion from 1.5 to 4 nm by changing the alkaloid concentration. These chirally coated platinum colloids function in quasi‐homogenous phases as enantioselective hydrogenation catalysts for ethylpyruvate (76% ee ), and no structure sensitivity was observed.