Preparation, structure and catalytic activity of palladium(II) complexes with a carboxyferrocenylphosphine and an ortho-metallated C,N-ligand

The ortho-palladated dimer trans-[{Pd(mu-Cl)(C6H4CHNMe2-kappa(2)C(1), P)}(2)] (1) reacts with methyl 1'-(diphenylphosphino)ferrocenecarboxylate (2) under bridge cleavage to afford [SP-4-4]-[PdCl(C6H4CH2NMe2-kappa(2)C(1), P){Fe(eta(5)-C5H4PPh2-kappaP)(eta(5)-C5H4CO2Me)}] (3) while a reaction between the cationic complexes [Pd(C6H4CHNMe2-kappa(2)C(1), P)(MeCN)(2)]X (4, X = ClO4 (a) and BF4 (b)) with 2 gives the products of replacement of one acetonitrile ligand trans to nitrogen, [SP-4-3]-[Pd(C6H4CHNMe2-kappa(2)C(1), P){Fe(eta(5)-C5H4PPh2-kappaP(eta(5)-C5H4CO2Me)}(MeCN)]X (5a, 5b). The crystal structures of 4a and 5a have been determined by X-ray crystallography. Compounds 3, 5b and other in situ generated complexes with the related ferrocene phosphines were tested as catalysts in Suzuki-Miyaura coupling of 4-bromotoluene and phenylboronic acid. (C) 2004 Elsevier Ltd. All rights reserved.