Substrate scope of α,β-unsaturated acceptors a,b. a Reaction conditions: substrate 2 (0.3 mmol), Me2PhSi-B(pin) 1 (1.2 equiv.), CS@Cu(acac)2 (5 mol % Cu loading), 4-picoline (6 mol %), H2O (2 mL), room temperature, air, 12 h; b Isolated yields were listed.