The addition of bis (pinacolato) diboron [(Me4C2O2) B–B (O2C2Me4)] to α, β-unsaturated carbonyl compounds giving β-boryl carbonyl compounds and the addition to terminal alkynes yielding either 2-boryl-1-alkenes or 1-boryl-1-alkenes were carried out in DMF at room temperature in the presence of CuCl and AcOK. The transmetalation between diboron and [Cu (Cl) OAc] K generating a borylcopper species was proposed as the key step in the ...