in tetrahydrofuran; hexane (argon); stirring (room temp., 3 h); solvent removal (vac.), chromy. (SiO2; hexane); yield is for 2 steps; elem. anal.;

in tetrahydrofuran (Ar); standard Schlenk technique; soln. of Fe complex in THF was treatedwith W complex; mixt. was stirred at room temp. for 24 h; evapd.; chromd. (alumina, petroleum ether; petroleum ether/CH2Cl2, 4/1);elem. anal.;

in tetrahydrofuran under N2, to soln. of W(CO)5(THF) in THF added soln. of C4H4B(Ph)(NH3) in THF, kept at 65°C for 5 h; evapd.(vac.), extd.(pentane), filtered, concd., cooled(-30°C), chromd. (Al2O3/7percent H2O(water-cooled, light protected column); pentane, pentane/ether), concd.(vac.), dried(1E-5 bar/-78°C), sublimed(1E-5 bar), crystd.(hexane); elem. anal.;

in tetrahydrofuran under N2 atm. soln. (W(CO)5(THF)) in THF was added to soln. (18-crown-6-K)(W(CO)5(P(C6F5)2)) in THF at -50°C, soln. was stirred for 6 h and allowed to rich to room temp.; soln. was evapd. to dryness in vacuo, residue was extd. with THF, Et2O was added, soln. was filtered and evapd., residue was washed with hexane;

1: tetrahydrofuran; diethylene glycol dimethyl ether; methanol 2: not given View Scheme

in tetrahydrofuran; diethylene glycol dimethyl ether byproducts: THF; Ar atmosphere, addn. of THF soln. of tungsten complex to CH3O(CH2)2O(CH2)2OCH3 soln. of KSCN (10 min), stirring (room temp., 24 h); removement of volatiles (vacuum), addn. (pentane), filtration, washing (n-pentane), drying (vacuum);

in tetrahydrofuran under N2; W-phenanthroline complex dissolved in THF; cooled in ice bath (0-5°C); soln. of W(CO)5(THF) in THF added dropwise; 4 h; evapd. to small vol.; n-hexane added; detd. by IR spectroscopy;

in tetrahydrofuran Fe-complex dissoln. in in situ prepared W-complex soln., solvent removal (vac.), ppt. extn. (CH2Cl2), concd. ext. chromy. (SiO2 column, elutionwith light petroleum ether into several fractions); product eluat boiling down to dryness (vac., 20°C), residue dissoln. (CH2Cl2), heptane addn., soln. vac. concn., keeping at -18°Cfor 2 d, crystals sepn. (decantation), washing (cold heptane), vac. drying;

in tetrahydrofuran Fe-complex dissoln. in in situ prepared W-complex soln., solvent removal (water-jet pump, 25°C), ppt. extn. (CH2Cl2), concd. ext. chromy. (SiO2 column, elution with light petroleum ether into several fractions); product eluat boiling down to dryness (vac., 20°C), residue dissoln. (CH2Cl2), heptane addn., soln. vac. concn., keeping at -18°Cfor 2 d, crystals sepn. (decantation), washing (cold heptane), vac. drying;

in tetrahydrofuran byproducts: W(CO)6; Ar-atmosphere; equimolar amts.; dropwise addn. of phosphaalkyne to mixt.of metal complexes (-21°C, during 4 h), warming to 0°C; solvent removal (0.001 Torr), sublimation off of (t-BuO)3WCt-Bu and W(CO)6 (50°C, 0.001 Torr), dissoln. in pentane, filtration, vol. reduction (vac.), crystn.; elem. anal.;