Highly enantioselective asymmetric reduction of aromatic ketimines promoted by chiral enantiomerically pure sulfoxides as organocatalysts

Optically pure hetero-organic organocatalysts, bearing a hydroxy moiety, a stereogenic sulfinyl group and a chiral amine moiety, have revealed high catalytic activity in the asymmetric reduction of various N-aryl ketimines leading to the corresponding chiral amines. Desired products were formed in high chemical yields (up to 95%) and with ee’s up to 97%. The influence of particular stereogenic centres on the stereochemical outcome of the reduction reaction is discussed.