Methylbenz[e]indenyl asymmetric ansa-metallocene and silylamido zirconium complexes

Abstract

2-(2-Methylbenz[e]indenyl)-2-cyclopentadienyl-propane [MeC13H8CMe2C5H5] (1) (MBICMe2Cp), was synthesized by reaction of LiMBI with 6,6-dimethylfulvene. The silyl derivatives [MeC13H8SiMeRCl] (R=Me 2, H 4) were isolated by reaction of 2-methylbenz[e]indene (LiMBI) with SiMeRCl2 and further reactions of 2 and 4 with NaCp afforded the silyl-bridged compounds [MeC13H8SiMeRC5H5] (R=Me 3, H 5). Metallation of 1 and 3 with 2 equiv. of LiBu gave the dilithium salts Li2[MeC13H7EMe2C5H4)] (E=C 6, Si 7) which were reacted with ZrCl4(THF)2 to obtain the ansa-metallocenes [Zr(MeC13H7EMe2C5H4)Cl2] (E=C 8, Si 9). A similar reaction of 5 with 2 equiv. of LiBu provided a mixture of the two diastereomers [Zr{MeC13H7SiMeBuC5H4}Cl2] (10a, 10b). Analogous metallation of [MeC13H8SiMe2(NH-t-Bu)] gave Li2[MeC13H7SiMe2(N-t-Bu)] which was used to prepare the amidosilyl derivatives [M{MeC13H7SiMe2η-(N-t-Bu)}Cl2] (M=Zr 11, Ti 12) by reaction with ZrCl4(THF)2 and TiCl3(THF)3 and further oxidation with PbCl2 (Ti). All of the new complexes were characterized by elemental analysis and NMR spectroscopy, and the molecular structures of complexes 9 and 10a were studied by X-ray diffraction methods.