Facile Conversion of an Appended Silylamido to a Silyloxy Ligand via Isocyanate Elimination. Synthesis of {[(C₅Me₄)SiMe₂O]Zr(η²-O₂CMe)(μ-O₂CMe)}₂ via the Carboxylation of [(C₅Me₄)SiMe₂(N-t-Bu)]ZrMe₂

The reaction of 2 equiv of CO₂ with [(C₅Me₄)SiMe₂(N-t-Bu)]ZrMe₂ proceeds with the formation of {[(C₅Me₄)SiMe₂(N-t-Bu)]Zr(η²-O₂CMe)(μ-O₂CMe)}₂ (2), which reacts with additional CO₂ to afford {[(C₅Me₄)SiMe₂O]Zr(η²-O₂CMe)(μ-O₂CMe)}₂ (3) with the concomitant elimination of OCN-t-Bu. The formation of OCN-t-Bu was confirmed by a combination of GC/MS and IR measurements; the molecular structures of 2 and 3 were determined by X-ray crystallography.