Catalytic Enantioselective Aza-Reformatsky Reaction with Cyclic Imines

A catalytic highly enantioselective aza-Reformatsky reaction with cyclic aldimines and ketimines for the synthesis of chiral β-amino esters with good yields and excellent enantioselectivities is reported. A readily available diaryl prolinol is used as a chiral ligand, ZnMe₂ as a zinc source and ethyl iodoacetate as reagent in the presence of air atmosphere. The reaction with cyclic ketimines generates a quaternary stereocenter with excellent levels of enantioselectivity. Furthermore, five-membered N-sulfonyl ketimines were used as electrophiles with good enantiomeric excesses, under the optimized reaction conditions. Moreover, several chemical transformations were performed with the chiral β-amino esters.