1: Cp2TiCl2 With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 1 h; 2: hex-3-yne in tetrahydrofuran; hexane T=-10°C; 3 h; 3: benzonitrile-α-13C in tetrahydrofuran; hexane 1 h; Heating;