in dichloromethane N2 atmosphere, addn. of soln. of stannyl compound to soln. of borane at -65 to -75°C (90 min), slow warming to room temp., stirring (25°C., 12 h); removement of solvent (25°C, 12 Torr) and Me3SnBr (30°C, 1E-2 Torr or 53-55°C, 12 Torr), MeN(BBr(C4H9))2,MeN(SnMe2Br)(BMeBr)/C4H9B(MeB)r ratio 8:2;

in pyridine-D5 Substitution; 120 h; Product distribution;