Complexes cis-[PdCl2(OSMeR)2] (R=Me, Ph, and C6H4Me-4) in attempted asymmetric cyclometalation of dimethylaminomethylferrocene

Two types of monocationic Pd(II) complexes are reported, which contain either the functional P,O phosphine ligands Ph2PCH2C(O)Ph or Ph2PCH2C(O)NPh2 or an anionic chelating phosphino enolate. The first set of complexes includes [)Ph}(PPh3)](PF6) (1), [)Ph}(PCy3)](PF6) (2), [)NPh2}(PPh3)](PF6) (3), and the second [Ō)Ph}(SMe2)2](PF6) (5), which was obtained by an interesting ligand redistribution reaction between cis-[Ō)Ph}2] and [Pd(SMe2)4](PF6)2. Compounds 1 and 5 display catalytic activity for ethylene dimerization. A preliminary study on ethylene/CO copolymerization with complexes 1–3 identified compound 1 as a catalyst precursor. This led to the in situ preparation of an active species for ethylene/CO copolymerization, starting from a Pd(0) precursor and appropriate ligands. The structures of complexes 2 and 5 have been determined by X-ray diffraction.