copper(l) iodide; triethylamine; tetrakis(triphenylphosphine) palladium(0) in N,N-dimethyl-formamide T=22 - 24°C;

pyridine; tetrabutyl ammonium fluoride; pyridine hydrogenfluoride in tetrahydrofuran T=20°C; 16 h;

1: 91 percent / diisopropyl azodicarboxylate; triphenylphosphine / tetrahydrofuran / 6 h / 0 - 20 °C 2: 96 percent / Et3N; CuI / Pd(PPh3)4 / dimethylformamide / 22 - 24 °C View Scheme

1.1: 1H-imidazole / N,N-dimethyl-formamide / 0.17 h / 20 °C 1.2: 18 h / 20 °C 2.1: copper(l) iodide; tetrakis(triphenylphosphine) palladium(0); triethylamine / N,N-dimethyl-formamide / 16 h / 20 °C / Inert atmosphere 3.1: triethylamine / N,N-dimethyl-formamide / 1 h / -55 °C 4.1: N,N-dimethyl-formamide / -55 - 20 °C 5.1: pyridine; tetrabutyl ammonium fluoride; pyridine hydrogenfluoride / tetrahydrofuran / 16 h / 20 °C View Scheme

1: copper(l) iodide; tetrakis(triphenylphosphine) palladium(0); triethylamine / N,N-dimethyl-formamide / 16 h / 20 °C / Inert atmosphere 2: triethylamine / N,N-dimethyl-formamide / 1 h / -55 °C 3: N,N-dimethyl-formamide / -55 - 20 °C 4: pyridine; tetrabutyl ammonium fluoride; pyridine hydrogenfluoride / tetrahydrofuran / 16 h / 20 °C View Scheme

1: triethylamine / N,N-dimethyl-formamide / 1 h / -55 °C 2: N,N-dimethyl-formamide / -55 - 20 °C 3: pyridine; tetrabutyl ammonium fluoride; pyridine hydrogenfluoride / tetrahydrofuran / 16 h / 20 °C View Scheme

1: 78 percent / DMAP / pyridine / 6.5 h / 22 - 24 °C 2: 68 percent / LiOH*H2O / methanol; tetrahydrofuran / 1.33 h / 22 - 24 °C 3: pyridine / 2.5 h / 22 - 24 °C 4: 0.057 g / CF3CO2H / CH2Cl2 / 0.5 h / 22 - 24 °C View Scheme