Synthesis and Characterization of Methoxylated Oligosilyl Group 4 Metallocenes.

New methoxylated oligosilyl-substituted metallocenes were synthesized by the reaction of two oligosilanides with different metallocene dichlorides (M = Ti, Zr, and Hf). The first investigated tris(trimethoxysilyl)silanide [(MeO) 3 Si] 3 SiK ( 1 ) underwent a selective monosubstitution to the respective oligosilyl-decorated metallocenes [(MeO) 3 Si] 3 SiMClCp 2 ( 2 - 4 ). Surprisingly, the attempted disilylation with this silanide was not possible. However, in the case of titanocene dichloride, a stable radical [(MeO) 3 Si] 3 SiTiCp 2 ( 5 ) was formed. The unsuccessful isolation of bisilylated metallocenes encouraged us to investigate the reactivity of another silanide. Therefore, we synthesized a hitherto unknown disilanide K[(MeO) 3 Si] 2 Si(SiMe 2 ) 2 Si[(MeO) 3 Si] 2 K ( 8 ), which was accessible in good yields. The reaction of compound 8 and different metallocene dichlorides (M = Ti, Zr, and Hf) gave rise to the formation of heterocyclic compounds 9 - 11 in good yields.