Copper-Catalyzed Asymmetric Protoboration of β‑Amido­acrylo­nitriles and β‑Amidoacrylate Esters: An Efficient Approach to Functionalized Chiral α‑Amino Boronate Esters

A copper-catalyzed asymmetric protoboration of both Z-β-amido­acrylonitriles and ethyl E-β-amido­acrylates using bis­(pinacolato)­diboron has been developed for the first time. The process tolerates a vast array of substrates, delivering a series of stable functionalized chiral α-amino boronate esters in good yields and enantioselectivities under mild reaction conditions. The current method is also applicable for gram-scale synthesis without erosion of enantioselectivity. This work provides an attractive and complementary approach to synthesizing enantioriched chiral α-amino boronate esters.