Stereospecific synthesis of a metallo-enolate: E-[Zr{OC(SiMe3)CHAr}Cl(η-C5H5)2](structurally characterised)via carbonylation of [Zr{CH(SiMe3)Ar}Cl(η-C5H5)2](Ar = 9-anthryl)

Abstract

Treatment of Li{CH(SiMe₃)Ar}(tmeda)(Ar = 9-anthryl, tmeda = Me₂N[CH₂]₂NMe₂) with zirconocene(IV) chloride in tetrahydrofuran at 20 °C affords [Zr{CH(SiMe₃)Ar}Cl(η-C₅H₅)₂], which rapidly reacts with carbon monoxide (P_CO 1 atm, 20 °C) in toluene to afford exclusively the E-metallo-enolate [Zr{OC(SiMe₃)CHAr}Cl(η-C₅H₅)₂], having Zr–O 1.950(4)Å and < Zr–O–C 157.7(3)°.