hexamethyl-distannane

n-C4H9Li in diethyl ether; hexane (Ar); a soln. of n-BuLi in hexane added dropwise at -78°C to an ether soln. of 4-bromopyridine, reacted, Me3SnCl in ether added at -78°C, stirred at -78°C, warmed slowly to room temp.; washed (H2O), the org. phase dried over MgSO4, solvent-removed, chromd. (silica gel, EtOAc/hexane); obtained as an oil;

sodium in ammonia Irradiation (UV/VIS); (CH3)3SnCl was dissolved in ammonia, Na metal was added until a blue color persisted for 5 min, when the blue color dissapeared, phosphate esterwas added, the mixt. was UV-irradiated with stirring for 5 h; excess of CH3I was added, NH3 was evapd., the residue was treated with water, extd. with ether, washed with aq. satd. soln. of NaCl, dried over MgSO4, recrystd. in ethanol;

NH4Cl; n-BuLi in diethyl ether; hexane under an inert atm. and strictly anhyd. conditions; at -40°C, (CH3)3SnCl in ether at room temp.; after stirring for 1 h satd. aq. NH4Cl soln.; in org. layer 4-(trimethyltin)pyridine(trimethyltin) chloride; the liq. was distd. under reduced pressure;

bis-triphenylphosphine-palladium(II) chloride; lithium chloride in toluene T=110°C; 71 h;

bis-triphenylphosphine-palladium(II) chloride; lithium chloride in toluene T=110°C;

in benzene 0.5 h;

chloro(cyclohexanecarbonyl)bis(triphenylphosphine)palladium(II) in benzene 3 h; Heating;

bis-triphenylphosphine-palladium(II) chloride; lithium chloride in toluene T=110°C;

tetrakis(triphenylphosphine) palladium(0) in toluene 5 h; Heating;