copper(l) iodide; tri-tert-butyl phosphine; palladium diacetate; potassium carbonate in N,N-dimethyl-formamide T=100°C; Sonogashira coupling; 24 h; Inert atmosphere;

copper(l) iodide; tri-tert-butyl phosphine; tetrabutylammomium bromide; palladium diacetate; potassium carbonate in water; N,N-dimethyl-formamide T=100°C; Sonogashira coupling; 24 h; Inert atmosphere;

copper(l) iodide; bis(benzonitrile)palladium(II) dichloride; tri-tert-butyl phosphine; potassium carbonate in N,N-dimethyl-formamide T=100°C; Sonogashira coupling; 24 h; Inert atmosphere;

1: 97 percent / toluene-p-sulfonic acid / benzene / 3 h / Heating 2: 1.) n-BuLi, CuI, (CH3)2Se / 1.) THF, hexane -78 deg C, 3 h 2.) THF, hexane -78 deg C 70 min then rt 1 h 3: HCl / H2O; tetrahydrofuran; hexane / 15 h / Ambient temperature 4: 93 percent / NaOH, TEBA / tetrahydrofuran / 4 h / Ambient temperature 5: 62 percent / silver(II) dipicolinate / benzene; H2O / Ambient temperature View Scheme