Reactivity of functionalised decamethyltitanocenes: Synthesis and structure of chiral monocyclopentadienyl titanium halogenides

• Unconventional substituted chiral titanocene complexes.
• Chiral ligands.
• Formation of the corresponding titanocene dihalogenides.
• Reaction with Et3N·3HF:dimeric anionic heptafluoride titanocene complexes.

The recently described unconventional substituted titanocene complex [Cp∗Ti{η5-C5Me3(CH2–CH(tBu)–η2-C2–CH(tBu)–CH2)}] (1) can be derivatised by simple means (Br2, HX with X = Cl, Br) to generate the titanocene dihalogenides 2-Br, 2-Cl, which give in a subsequent reaction besides Cp∗TiX3 (3-Br: X = Br, 3-Cl: X = Cl) the titanium complexes 4-Cl resp. 4-Br with one functionalised chiral cyclopentadienyl ligand. In the reaction of 1 with Et3N·3HF an analogous isostructural titanocene dihalogenide 2-F as well as the unusual dimeric anionic heptafluoride 5 are formed. All complexes have been characterised spectroscopically, and X-ray crystal structure determinations were performed for 4-Cl and 2-F.

Cp∗Ti{η5-C5Me3(CH2–CH(tbu)–η2-C2–CH(tbu)–CH2)} (1) reacted with an excess of HX (X = Cl, Br) resp. Et3N·HF to afford the titanocene dihalogenides in the first stage and a subsequent acidolysis of the Cp∗ ligand resulted in the chiral functionalised monocyclopentadienyl complexes 4. For X = F a dimerization gives the fluoride bridged complex 5.Figure optionsDownload as PowerPoint slide