Synthesis and Application of New Chiral Ligands for the Asymmetric Borane Reduction of Prochiral Ketones

摘要

Two chiral nonracemic γ-amino alcohols, ephedrine thiol and the corresponding (thio)-phosphoramidates and (thio)-phosphinamides have been examined as catalysts for the reduction of propiophenone by various boranes. Up to 95% e.e. can be obtained with the phosphorus derivatives.