in tetrahydrofuran byproducts: Cu; under N2; soln. of Ti-Fe complex in THF at -10°C mixed with CuCl2 (molar ratio 1:1.07) in THF; stirred at -10°C for 30 min; volatiles removed in vac.; sepd. by chromy. (Kieselgur, -30°C, n-pentane); eluted with Et2O (Fe complex) and THF (Ti complex);