Optical rotation per refractive index unit, or enantiomeric (e) factor, for screening enantioselective catalysts through asymmetric activation or carbohydrates

A super high-throughput screening (SIFTS) system can be constructed by comb ining high-performance liquid chromatography (HPLC), optical rotation (OR), and refractive index unit (RIU) to determine not only the enantioselectivi ty of the addition of diethylzinc to an aliphatic aldehyde catalyzed by a b inaphthol-zinc complex through asymmetric activation with chiral Schiff bas es, but also the enantiopurity of a carbohydrate. The enantiomeric (e) fact or, which we define here as optical rotation per refractive index unit, is linearly related to the percent enantiomeric excess (%ee) and is independen t of concentration. (C) 2000 Wiley-Liss, Inc.