Basic CuCO3/ligand as a new catalyst for 'on water' borylation of Michael acceptors, alkenes and alkynes: application to the efficient asymmetric synthesis of β‐alcohol type sitagliptin side chain

The efficient 'on water' β‐borylation using bis(pinacolato)diboron agent was achieved with a newly developed catalytic system based on basic copper carbonate and various ligands. The catalytic system was used for β‐borylation of various Michael acceptors, alkenes and alkynes. The presented methodology was successfully applied to the novel synthesis of β‐alcohol type sitagliptin side chain precursor via water‐based highly enantioselective β‐borylation followed by an oxidation process.