Chiral Copper(II)‐Catalyzed Enantioselective Boron Conjugate Additions to α,β‐Unsaturated Carbonyl Compounds in Water

Copper pins on the boron: The enantioselective 1,4-addition of diboron to α,β-unsaturated compounds proceeds smoothly in the presence of catalytic amounts of Cu(OH)2 and chiral 2,2′-bipyridine ligand in water. A wide substrate scope of α,β-unsaturated carbonyl compounds, including acyclic, cyclic, and β,β-disubstituted enones, α,β-unsaturated esters, amides, and a nitrile, has been shown.