2: tetrahydrofuran View Scheme

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.;

n-BuLi in dichloromethane under N2 or Ar; n-BuLi in hexane added (-80°C) to alkyne in THF; stirred (-100°C, 20 min); W 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, 1:4); elem. anal.;

in tetrahydrofuran inert atmosphere; stirring (room temp., 6 h); IR spectroscopy;

in tetrahydrofuran inert atmosphere; stirring (room temp., 6 h); IR spectroscopy;

in tetrahydrofuran 25°C, 1:1 molar ratio; evapn. (high vac.), recrystn. (THF/hexane, -28°C); elem. anal.;

n-BuLi in dichloromethane under N2 or Ar; n-BuLi in hexane added (-80°C) to alkyne in THF; stirred (-100°C, 20 min); W 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, 1:4); elem. anal.;

in tetrahydrofuran (Ar); standard Schlenk technique; soln. of Fe complex in THF was added to W complex; mixt. was stirred at room temp. for 24 h; W complex (5 equiv.) was added; reacted for 2 d; solvent stripped out (vac.); sublimed; chromd. (alumina, petroleum ether; CH2Cl2; CH2Cl2/CH3CN, 1/1); elem. anal.;

in tetrahydrofuran byproducts: Me2S; under N2; W-complex in THF added to Fe-complex in THF, stirred overnight at room temp.; dried (vac.), dissolved in CH2Cl2, chromy. (alumina; eluent: CH2Cl2:petrolether = 1:1 (v/v)), crystn.;