Enantioselective Synthesis of β-Substituted β-Amino Esters

Significance

The article describes a practical large-scale enantioselective synthesis of β-aminoesters from corresponding aldehydes, using chiral phenylglycinol as a chiral auxiliary. The 1,2-addition to the imines formed from an aldehyde and phenylglycinol proceeds with high diastereoselectivity. The products are important subunits of many biologically active compounds. The authors also reported a useful multikilogram-scale protocol for the preparation of the Reformatsky reagent (BrZnCH₂CO₂ t-Bu×THF).