n-butyllithium; niobium bromide in tetrahydrofuran T=-78 - 25°C; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

n-butyllithium; niobium bromide in tetrahydrofuran T=-78 - 25°C; Yield given. Yields of byproduct given;

1: diisopropylamine, n-BuLi / tetrahydrofuran / 0.5 h / -78 °C 2: nickel(II) bromide, n-BuLi / tetrahydrofuran / -78 - 25 °C View Scheme

titanium tetrachloride in dichloromethane 1,) 30 min, -78 deg C, 2.) 10 h, 0 deg C, 3.) 11 h, room temp.; Yield given. Yields of byproduct given. Title compound not separated from byproducts;