potassium carbonate in methanol T=20°C; 48 h;

bis-triphenylphosphine-palladium(II) chloride; copper(l) iodide; 1,8-diazabicyclo[5.4.0]undec-7-ene in toluene T=20°C; Sonogashira Cross-Coupling; 24 h;

1: Pd(PPh3)2Cl2; CuI; triethylamine / tetrahydrofuran / 15 h / 20 °C 2: 80 percent / tetra-nibutylammonium fluoride / CH2Cl2; tetrahydrofuran / 2 h / 0 °C View Scheme

1.1: iodine; mercury(II) oxide / ethanol / 24 h / 20 °C 2.1: copper(l) iodide; [palladium(II)(bis(triphenylphosphanyl))dichloride]; triethylamine / tetrahydrofuran / 0.83 h / 20 °C / Inert atmosphere 2.2: 36 h / 20 °C 3.1: tetrabutyl ammonium fluoride / tetrahydrofuran; dichloromethane / 2.5 h / 0 - 5 °C View Scheme

1: 80 percent / PdCl2(PPh3)2; PPh3; CuI / triethylamine / Heating 2: 97 percent / K2CO3 / methanol / 48 h / 20 °C View Scheme

Pd(0) catalyst Sonogashira coupling;