Reversal of enantioselectivity by adding Ti(OiPr)4: novel sulfamide-amine alcohol ligands for the catalytic asymmetric addition of diethylzinc to aldehydes

Novel sulfamide-amine alcohols (6) were applied to the catalytic asymmetric addition of diethylzinc to aldehydes, providing (S)-products in high yields and good enantioselectivities. These sulfamide-amie alcohols together with Ti(OiPr)4 were shown to obtain the (R)-products in significant enantiomeric excesses and high yields.