| abstract |
A process for the preparation of compounds of the formula I is described wherein R is an anion C₅H₄R¹ or C₉H₇, R¹ is hydrogen, C₁-C₆-alkyl or halogen, R² is an η-arene, X is a q-valent anion and q is 1, 2, 3 or 4, by reacting ferrocene or a ferrocene derivative (C₅H₄R³) Fe (C₅H₄R¹) or (C₉H₇R) ₂Fe, where R³ is one of the meanings of R¹, with at least one mole of a π-arene R² in the presence of at least 1.4 mol of a mixture of Al and Ti-IV halide or (C₅H₄R¹) -Ti-IV halide and optionally in the presence of a metallic reducing agent, optionally followed by the exchange of the anion X q⊖ in a manner known per se , with the proviso that the Lewis acid mixture contains at least 0.1 mol of Al halide and at least 0.1 mol of the Ti-IV halide in question and that Quantities each relate to one mole of ferrocene (derivative).n n n With a suitable choice of the amounts of reactants, the process is suitable for the simultaneous preparation of compounds of the formula I and of titanocene dihalides. |