Novel Synthesis of ansa-Metallocenes via the Reductive Dimerization of Fulvenes with Group 4 Metal Divalent Halides1
摘要:
Substituted ethylene-bridged ansa-metallocenes of group 4 dihalides can be prepared in high yields by the interaction of the titanium zirconium, or hafnium dihalide with 2 equiv of the appropriate fulvene. The requisite metal dihalides are readily produced by the alkylative reduction of the metal tetrahalide with 2 equiv of an alkyllithium reagent in THF or in toluene.