in diethyl ether; pentane byproducts: LiBr, B(CH3)3; (CH3)3SiN(BBrCH3)2 in pentane added to Li-compd. in ether at -40°C, soln. stirred for 24 h; solvent evapd., insol. material filtered, filtrate condensed, it contained (CH3)2BNCH3B(CH3)2, identified by NMR, non volatile residue after distn. at 70°C bath temp./E-3 Torr gave pentamethyl-Si derivative; elem. anal.;

in dichloromethane T=25°C; Substitution; 12 h;

in dichloromethane not separable mixture;

in dichloromethane N2 atmosphere, addn. of soln. of borane to soln. of stannyl compound at -75°C (60 min), slow warming to room temp., stirring (25°C, 12 h); removement of solvent (25°C, 12 Torr), removement of Me3SnBr (30°C, 1E-2 Torr or 53-55°C, 12 Torr);

in dichloromethane Heating;