magnesium in diethyl ether; toluene dropwise addn. of a soln. of C6H5Si(CH3)2CH2Cl in ether to heated Mg with stirring under N2; refluxing for 1 h; addn. of ether; dropwise addn. of the ether soln. to a soln. of SnCl4 in dry toluene at 0°C; 15 h at room temp.; reflux, 3h; N2 atm.;; cooling; slow addn. to NH4Cl/ice; stirring; ppt. was filtered off and washed with ether; sepn. of the org. layer; extn. of the aq. layer with ether; drying of the combined org. filtrates; evapn.; repeated recrystn. from petroleum ether; elem. anal.;;

in diethyl ether; toluene soln. of ligand in Et2O was added dropwise to soln. of SnCl4 in toluene at room temp. under N2, left 15 h at room temp., refluxed for 3 h, cooled to 0°C; decomposed with satd. soln. of NH4Cl, sepd., aq. layer was extd. with Et2O, dried over MgSO4, solvent was removed under reduced pressure, recrystd. from n-heptane;

in diethyl ether; toluene soln. of ligand in Et2O was added dropwise to soln. of SnCl4 in toluene at 0°C under N2, stirred for 1.5 h at room temp., refluxed for 3 h, left for 15 h at room temp., cooled to 0°C; decomposed with satd. soln. of NH4Cl, sepd., aq. layer was extd. with Et2O, dried over MgSO4, solvent was removed under reduced pressure;