Nucleophilic Attack of Carbonyl-Stabilized Phosphorus Ylides on 1,5-Cyclooctadiene Complexes of Palladium and Platinum

Carbonyl-stabilized phosphorus ylides R₃PCHC(O)R‘ (R = Ph, Tol-p; R‘ = OEt, OMe, NMe₂) react with the 1,5-cyclooctadiene complexes [MCl₂(cod)] (M = Pt, Pd; cod = C₈H₁₂ = 1,5-cyclooctadiene) to give the monomeric cyclooctenyl complexes [MCl₂{C₈H₁₂{CH(PR₃)C(O)R‘}}]. The ylides attack in an exo fashion to give complexes which can be regarded as metalated phosphonium salts. Reactions involving the replacement of one or both chloro ligands with a neutral ligand are discussed. The crystal structures of complexes [PtCl₂{C₈H₁₂{CH(PPh₃)CO₂Me}}] and [Pt{C₈H₁₂{CH(PPh₃)CO₂Me}}(py)₂](CF₃SO₃)₂ are reported.