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

Abstract

Reported herein is an efficient copper(I)-catalyticsystem for the diastereo- and enantioselective 1,2-addition of1,1-bis[(pinacolato)boryl]alkanes to protected imines to affordsynthetically valuable enantioenriched b-aminoboron com-pounds bearing contiguous stereogenic centers.The reactionexhibits abroad scope with respect to protected imines and 1,1-bis[(pinacolato)boryl]alkanes,thus providing b-aminoboro-nate esters with excellent diastereo- and enantioselectivity.Thesynthetic utility of the obtained b-aminoboronate ester was alsodemonstrated.