piperidine; copper(l) iodide; triphenylphosphine; bis-triphenylphosphine-palladium(II) chloride in tetrahydrofuran T=20°C; Sonogashira coupling reaction; 24 h;

1: 98 percent / periodic acid dihydrate; iodine / acetic acid; H2O; H2SO4 / 4 h / 60 - 65 °C 2: 53 percent / NaOH / triethylbenzylammonium chloride / dimethylsulfoxide; H2O / 6 h / 20 °C 3: 27.7 percent / piperidine; triphenylphosphine; cuprous iodide / dichlorobis(triphenylphosphine)palladium(II) / tetrahydrofuran / 24 h / 20 °C View Scheme

1: 53 percent / NaOH / triethylbenzylammonium chloride / dimethylsulfoxide; H2O / 6 h / 20 °C 2: 27.7 percent / piperidine; triphenylphosphine; cuprous iodide / dichlorobis(triphenylphosphine)palladium(II) / tetrahydrofuran / 24 h / 20 °C View Scheme

1: 74.4 percent / NaOH; triethylbenzylammonium chloride / dimethylsulfoxide; H2O / 6 h / 20 °C 2: 88.2 percent / triphenylphosphine; cuprous iodide / dichlorobis(triphenylphosphine)palladium(II) / triethylamine / 6 h / Heating 3: 86.9 percent / potassium hydroxide / propan-2-ol / 3 h / Heating 4: 27.7 percent / piperidine; triphenylphosphine; cuprous iodide / dichlorobis(triphenylphosphine)palladium(II) / tetrahydrofuran / 24 h / 20 °C View Scheme

1: 88.2 percent / triphenylphosphine; cuprous iodide / dichlorobis(triphenylphosphine)palladium(II) / triethylamine / 6 h / Heating 2: 86.9 percent / potassium hydroxide / propan-2-ol / 3 h / Heating 3: 27.7 percent / piperidine; triphenylphosphine; cuprous iodide / dichlorobis(triphenylphosphine)palladium(II) / tetrahydrofuran / 24 h / 20 °C View Scheme

1: 86.9 percent / potassium hydroxide / propan-2-ol / 3 h / Heating 2: 27.7 percent / piperidine; triphenylphosphine; cuprous iodide / dichlorobis(triphenylphosphine)palladium(II) / tetrahydrofuran / 24 h / 20 °C View Scheme