1: 80 percent / triphenylphosphine (polymer-bound); carbon tetrachloride / 24 h / Heating 2: 4.42 g / sodium azide / acetic acid / 4 h / 70 °C 3: 90 percent / tetrakis(triphenylphosphine)palladium(0) / dimethylformamide / 20 h / 80 °C 4: 80 percent / Raney nickel; sodium hypophosphite / pyridine; acetic acid; H2O / 63 h / 80 °C View Scheme