Electronic tuning of chiral diene ligands in iridium-catalyzed asymmetric 1,6-addition of arylboroxines to δ-aryl-α,β,γ,δ-unsaturated ketones.

Asymmetric addition of arylboroxines to δ-aryl-α,β,γ,δ-unsaturated ketones proceeded in the presence of an iridium catalyst coordinated with a chiral diene ligand to give high yields of δ-diaryl ketones with very high enantioselectivity.