Synthesis of Enantiopure o-Hydroxybenzylamines by Stereoselective Reduction of 2-Imidoylphenols: Application in the Catalytic Enantioselective Addition of Diethylzinc to Aldehydes

Enantiopure o-hydroxybenzylamines 2a–i were synthesized by diastereoselective reduction of the 2-imidoylphenols (R)-1a–i. Conformational analysis enabled the assignment of the absolute configurations of compounds 2a–i. The accessible o-hydroxybenzylamine (R,R)-2h serves as an effective catalyst precursor for highly enantioselective addition of diethylzinc to aliphatic and aromatic aldehydes. This pathway represents a practical and operationally very simple methodology for the enantioselective synthesis of both the enantiomers of secondary alcohols 7a–f.