190380-14-4Relevant academic research and scientific papers
Uncovering alternative reaction pathways taken by group 4 metallocene cations: Facile intramolecular CH activation of Cp-(dimethylamino)alkyl substituents by a methylzirconocene cation
Bertuleit, Axel,Fritze, Cornelia,Erker, Gerhard,Fr?hlich, Roland
, p. 2891 - 2899 (1997)
Alkyl- and aryllithium reagents add cleanly to the electrophilic carbon center C6 of 6-(N,N-dimethylamino)fulvenes to yield the corresponding substituted cyclopentadienyllithium systems Li[C5H4-CR1R2NMe2]. Subsequent treatment with ZrCl4·2THF gives the corresponding Cp-functionalized zirconocene dichlorides. These were reacted with methyllithium to give the (C5H4CR1R2NMe2) 2Zr(CH3)2 complexes 11a (R1 = R1 = CH3) and 11b (R1 = CH3, R2 = Ph), respectively. Treatment of 11 with tris(pentafluorophenyl)borane was carried out to generate the corresponding alkylmetallocene cations (12), which turned out to be unstable under the reaction conditions applied (-20 °C) with regard to liberation of 1 equiv of methane by CH activation at a methyl group adjacent to nitrogen and formation of the spiro-metallocene complex systems 13. CH activation may be a major reaction pathway open to alkylzirconocene cation systems under suitable reaction conditions.
