Copper(I)-Catalyzed Enantioselective Nucleophilic Borylation of Aldehydes: An Efficient Route to Enantiomerically Enriched α-Alkoxyorganoboronate Esters

The first catalytic enantioselective nucleophilic borylation of a C═O double bond has been achieved. A series of aldehydes reacted with a diboron reagent in the presence of a copper(I)/DTBM-SEGPHOS complex catalyst using MeOH as a proton source to give the corresponding optically active α-alkoxyorganoboronate esters with excellent enantioselectivities. Furthermore, the products could be readily converted to the corresponding functionalized chiral alcohol derivatives through stereospecific C–C bond forming reactions involving the stereogenic C–B bond.