Metallocenylcyclopentadienylide als Vorläufer für Heteropolymetallocene. Darstellung und Reaktionen von Ferrocenyl- und Kobaltoceniumyl-cyclopentadienylide

Abstract Convenient in situ preparations of ferrocenyl- and cobaltoceniumyl-cyclopentadienylide were achieved by two different synthetic routes. Ferrocenylcyclopentadienylide was prepared by lithiation of 1-(7-chlorobicyclo[2.2.1.]-hept-2-ene-7-yl)ferrocene. Spontaneous retro-Diels-Alder reaction gave the desired new compound. The cobalt analogue was synthesized by nucleopholic attack of sodium cyclopentadienylide on cobaltocenium, hydride-abstraction by triphenylmethyliumhexafluorophosphate and subsequent deprotonation with thallous ethoxide. Charaterisation of key synthons is given by NMR and MS data. Evidence for in situ generation of metallocenylcyclopentadienylides is confirmed by derivation to 1,1′- bisferrocenylcobaltocenium-hexafluorophosphate and 1,1′-ferrocenediyl-bis- cobaltocenium-bishexafluorophosphate.