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Updated: Apr 15, 2026

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
Formation of tri- and tetranuclear titanacycles through decamethyltitanocene-mediated intermolecular C-C coupling of
Lisanne Becker1, Perdita Arndt, Anke Spannenberg
1Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, 18059 Rostock (Germany).
Abstract:
The reactions of [Cp*2 Ti(η(2) -Me3 SiC2 SiMe3 )] (Cp*=η(5) -pentamethylcyclopentadienyl) with various dicyano compounds were investigated. Nitrile-nitrile CC couplings result in multinuclear complexes owing to the bifunctionality of the substrates. Applying 1,3- or 1,4-dicyanobenzene led to tri- and tetranuclear complexes of the rare 1-metalla-2,5-diaza-cyclopenta-2,4-dienes. These are potential catalysts and were tested in the ring-opening polymerization of ε-caprolactone. The reaction with adiponitrile as alkyl dinitrile afforded a trinuclear 1-metalla-2,5-diaza-cyclopent-3-ene through additional protonation of the nitrogen atoms. The structure and bonding of the products were investigated by X-ray crystallography and DFT analysis to understand the molecular organization in the macrocycles.
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