Enantioselective Catalytic Borane Reductions of Achiral Ketones: Synthesis and Application of New Rigid Catalysts Prepared from (R)-Phenylglycine and (S)-Phenylalanine

Exnantiocontrolled reduction of prochiral ketones with borane in the presence of homochiral amino alcohols 1 - 4 as enantioselective catalysts afforded the chiral corresponding secondary alcohols in moderate to high (55 to 88 %) optical yields.