Microwave‐Assisted Ligand‐Free Nickel‐Catalyzed β‐Boration of α,β‐Unsaturated Carbonyl Compounds with Bis(pinacolato)diboron

A simple and efficient ligand‐free nickel‐based catalytic system has been developed for the β‐boration of α,β‐unsaturated carbonyl compounds with bis(pinacolato)diboron. With catalyst loading of 10–15 mol%, a series of β‐boration products from chalcones and cinnamates was obtained rapidly in moderate to excellent yields within 3–30 minutes under a nitrogen atmosphere and microwave irradiation. The combination of hydroboration with microwave irradiation provided a convenient and rapid method to afford a boronate group at the β‐position of carbonyl.