Reactions of dimethylzirconocene complexes with a vicinal frustrated P/B Lewis pair

Abstract

The intramolecular vicinal frustrated P/B Lewis pair (FLP) Mes₂PCH₂CH₂B(C₆F₅)₂ readily abstracts a methyl anion equivalent from dimethylzirconocene to give the salt [Cp₂ZrCH₃]⁺ [Mes₂PCH₂CH₂B(CH₃)(C₆F₅)₂]⁻ that features phosphane coordination to the zirconium cation. The analogous reaction between this FLP and Cp*₂Zr(CH₃)₂ yields the analogous salt that, however, features a methyl bridged ([Zr]⋯H₃C–[B]) tight ion pair structure. Both these products were characterized by X-ray diffraction. They both undergo 1,2-[Zr⁺]/P addition to carbon dioxide. The [Cp₂ZrCH₃]⁺ containing compound also adds to benzaldehyde or to p-tolyl isocyanate to give the respective [Zr⁺]/P addition products which were characterized by X-ray diffraction.