In Situ Measurement of the Enantiomeric Excess of Alcohols and Amines under Asymmetric Reduction Reaction by 1H NMR

1H NMR, in situ, determines the enantiomeric excess of reduced chiral alcohols or amines without adding any auxiliary and workup. The percent ee data determined by this method agree well with those given by HPLC. This approach may be potentially applicable to many asymmetric reductions.