Abstract

The catalytic behaviour of different complexes of Palladium(II) containing mono or bidentate phosphorus or nitrogen ligands in the methoxycarbonylation reaction is examined. The pre-catalysts containing either a diphosphine ligand possessing a ferrocenyl backbone or a naphthyridine ligand attached to the same ferrocenyl backbone showed different catalytic activity for the reaction. Complexes containing the 1,1-bis(diphenylphosphino)ferrocene (dppf) ligand showed a better catalytic activity than the complex having the naphthyridine ligand in its structure. Various effects of the addition of triphenylphosphine to these pre-catalysts were observed. More than 99% conversion was achieved in the methoxycarbonylation of styrene using Pd(II) catalysts with ferrocenyl chelate derivatives, mostly with the Pd(dppf)Cl 2, [Pd(dppf)(MeCN) 2](BF 4) 2 and [Pd(dppf)PPh 3](BF 4) 2 complexes without the presence of triphenylphosphine as is usual in this reaction. The reactions were carried out under mild pressure and temperature conditions. Graphical Abstract: Complexes of the type Pd(dppf)Cl 2, [Pd(dppf)(MeCN) 2](BF 4) 2 and [Pd(dppf)PPh 3](BF 4) 2 were used as catalysts for the Methoxycarbonylation of styrene using mild pressure and temperature condition. The catalysts system showed more than 99% conversion in reactions without the presence of triphenylphosphine. [Figure not available: see fulltext.] © 2009 Springer Science+Business Media, LLC.