Synthesis, structure and reactivity of highly functionalized η1-stibaallyliron complexes [(OC)2(η5-C5Me5)Fe–Sb(Cl)C(OSiMe3)CPhR] (R = Ph, Me or c-C6H11)

Abstract

Insertion of one equivalent of methyl(phenyl)ketene or cyclohexyl(phenyl)ketene into the Sb–Si bond of [FeCp*(CO)₂{Sb(SiMe₃)₂}] afforded η¹-stibaallyliron complexes [(OC)₂(η⁵-C₅Me₅)Fe–Sb(SiMe₃)C(OSiMe₃) CR¹Ph] (R¹ = c-C₆H₁₁ or Me). The remaining Sb–Si bond was readily cleaved by C₂Cl₆ to give complexes [(OC)₂Cp*Fe–Sb(Cl)C(OSiMe₃)CR¹Ph]. Treatment of the latter where R¹ = Ph with LiSb(SiMe₃)₂·2.8thf, LiCCPh, or LiC(N₂)SiMe₃ resulted in the formation of compounds [(OC)₂Cp*Fe–Sb(R)C(OSiMe₃)CPh₂ [R = Sb(SiMe₃)₂, CCPh or C(N₂)SiMe₃]. The new compounds were characterized by elemental analyses and spectra (IR, ¹H, ¹³C, ²⁹Si NMR). The molecular structure of [(OC)₂Cp*Fe–Sb(Cl)C(OSiMe₃)CPh₂] was elucidated by a single crystal X-ray diffraction analysis.