Bis-alkenyl complexes of nickel, palladium and platinum from co-ordinated phosphino-enolates: X-ray structures of (R,S)-cis-[Pd{Ph2PCH[C(O)Ph][MeO2CCC(CO2Me)]}2] and [(o-C6H4CH2NMe2)Pd{Ph2PC{C(O)Ph][(MeO2C)CC(H)(CO2Me)]}]

Abstract

Three isomeric polyfunctional phosphine ligands may be generated by carbon–carbon coupling between enolato complexes of the type [L_n[graphic omittd])Ph}](M = Ni, Pd, Pt) and the alkyne MeO₂CCCCO₂Me; the thermal isomerisation of the (P, alkenyl) form either leads to a (P, alkyl) chelate or, after metal–carbon bond cleavage and H-shift, to a ligand rearrangement with regeneration of (P, O) co-ordination.