in pentane (N2); Schlenk technique; soln. of Fe complex in pentane was cooled to 0°C; soln. of B compd. in THF was added dropwise with stirring; soln. was stirred at 0°C for 4 h; volatiles removed (vac.); extd. (Et2O); filtered; silica gel added; volatiles removed (vac.); chromd. (Et2O/petroleum ether, 1/10); volatiles removed; recrystd. (pentane, -78°C);