Synthesis of C2-symmetrical bis-β-amino alcohols from ( R)-cysteine and their application in enantioselective catalysis

Abstract

Six new sulfur-containing C 2-symmetrical bis-β- primary and sec-amino- tert-alcohols have been synthesized from ( R)-cysteine and applied successfully in the enantiocontrolled catalytic addition of diethylzinc to benzaldehyde. The resulting 1-phenyl-1-propanol could be obtained in good enantiomeric excess of up to 94%. Using the same chiral auxiliaries in the enantioselective borane reduction of acetophenone afforded 1-phenyl-1-ethanol in enantiomeric excesses of up to 82%.