Diastereo- and Enantioselective Synthesis of β-Aminoboronate Esters by Copper(I)-Catalyzed 1,2-Addition of 1,1-Bis[(pinacolato)boryl]alkanes to Imines.

Reported herein is an efficient copper(I)-catalytic system for the diastereo- and enantioselective 1,2-addition of 1,1-bis[(pinacolato)boryl]alkanes to protected imines to afford synthetically valuable enantioenriched β-aminoboron compounds bearing contiguous stereogenic centers. The reaction exhibits a broad scope with respect to protected imines and 1,1-bis[(pinacolato)boryl]alkanes, thus providing β-aminoboronate esters with excellent diastereo- and enantioselectivity. The synthetic utility of the obtained β-aminoboronate ester was also demonstrated.