Addition and coupling reactions of bis(pinacolato)diboron mediated by CuCl in the presence of potassium acetate

The addition of bis(pinacolato)diboron [(Me4C2O2)B-B(O2C2Me4)] to alpha,beta-unsaturated ketones, esters, nitriles, or terminal alkynes and the coupling with allyl chlorides were carried out in DMF at room temperature in the presence of CuCl and AcOK. The transmetalation from boron to copper generating a B-Cu species was proposed as the key step of the reactions.