n-BuLi in dichloromethane under N2 or Ar; n-BuLi in hexane added (-80°C) to alkyne in THF; stirred (-80°C, 20 min); Cr complex in THF added; stirred (ambient temp., 30 min); solvent removed; dissolved in CH2Cl2; treated with Et3OBF4 (0°C); stirred (60 min); filtered at -20°C through silica layer using CH2Cl2 as eluent; solvent evapd.; sepd. by chromy. (silica, -20°C, pentane-CH2Cl2 2:1, 1:1 to 1:3); elem. anal.;

n-BuLi in dichloromethane under N2 or Ar; n-BuLi in hexane added (-80°C) to alkyne in THF; stirred (-80°C, 20 min); Cr complex in THF added; stirred (ambient temp., 30 min); solvent removed; dissolved in CH2Cl2; treated with Me3OBF4 (0°C); stirred (60 min); filtered at -20°C through silica layer using CH2Cl2 as eluent; solvent evapd.; sepd. by chromy. (silica, -20°C, pentane-CH2Cl2 2:1, 1:1 to 1:3); elem. anal.;

piperidine; copper (I) iodide; bis-triphenylphosphine-palladium(II) chloride 72 h; Heating;

n-BuLi in dichloromethane under N2 or Ar; n-BuLi in hexane added (-80°C) to alkyne in THF; stirred (-80°C, 20 min); W complex in THF added; stirred (ambienttemp., 30 min); solvent removed; dissolved in CH2Cl2; treated with Et3O BF4 (0°C); stirred (60 min); filtered at -20°C through silica layer using CH2Cl2 as eluent; solvent evapd.; sepd. by chromy. (silica, -20°C, pentane-CH2Cl2 2:1, 1:1 to 1:3); elem. anal.;

n-BuLi in dichloromethane under N2 or Ar; n-BuLi in hexane added (-80°C) to alkyne in THF; stirred (-80°C, 20 min); W complex in THF added; stirred (ambienttemp., 30 min); solvent removed; dissolved in CH2Cl2; treated with Me3O BF4 (0°C); stirred (60 min); filtered at -20°C through silica layer using CH2Cl2 as eluent; solvent evapd.; sepd. by chromy. (silica, -20°C, pentane-CH2Cl2 2:1, 1:1 to 1:3); elem. anal.;

tetrabutyl ammonium fluoride in tetrahydrofuran

potassium carbonate in methanol T=20°C;

1: 92 percent / Et2NH; Cu2I2 / PdCl2(PPh3)2 / 0.5 h / 40 °C 2: 61 percent / NaOH / toluene / 1 h / Heating View Scheme

sodium hydroxide in toluene 1 h; Heating;

1: 47 percent / POCl3 / 3 h / Heating 2: 92 percent / Et2NH; Cu2I2 / PdCl2(PPh3)2 / 0.5 h / 40 °C 3: 61 percent / NaOH / toluene / 1 h / Heating View Scheme