Bis(pentamethylcyclopentadienyl)metalldivinyl-Verbindungen des Titaniums, Zirconiums und Hafniums; Bildung von Titanacyclobutan- und Zirconacyclopent-2-en-Derivaten

Article abstract of DOI:10.1016/0022-328X(81)80005-8

Bis(pentamethylcyclopentadienyl)metal dichlorides, Cp2^*MCl2 (M=Ti, Zr, Hf), react with vinyllithium in the molar ratio 1/2 to form the corresponding divinyl compounds Cp2^*M(CH=CH2)2.The hafnium compound can be isolated pure.The titanium and zirconium compounds can be detected by low-temperature NMR spectroscopy, but they undergo rearrangements at room temperature.Cp2^*Zr(CH=Ch2)2 forms an equilibrium with as the zirconacyclopent-2-ene derivative whereas Cp2^*Ti(CH=CH2)2 surprisingly is converted quantitatively into which exhibits a titanacyclobutane derivative with an exocyclic methylidene group.