Chiral Bicyclic NHC/Cu Complexes for Catalytic Asymmetric Borylation of α,ß-Unsaturated Esters.

The potential of using chiral bicyclic NHC ligands that exhibit modularity was investigated in the Cu-catalyzed asymmetric borylation reaction of α,ß-unsaturated esters. After screening for ligands and optimization of the reaction conditions, the corresponding products were afforded with good enantioselectivities (up to 85% ee).