The construction of P-O/P-N ligands on platinum and palladium

A variety of diphenyldiphosphinites have been prepared in a very stable form as Pt-II or Pd-II complexes by adding diols to a solution containing cis-[MCl2(PPh2Cl)(2)] (M = Pt or Pd) preformed in situ from cis-[MCl2(1,5-COD)] (M = Pt; M = Pd) and PPh2Cl. This synthetic pathway can be used for diphosphinites derived from aliphatic 1,2 and 1,3 diols and also from the aromatic catechol. Besides the P-O bond, it is also shown here that the P-N bond can also be formed via nucleophilic attack of an amine group on coordinated PPh2Cl in the presence of a base resulting in some AMPP and BAMP complexes of Pt-II and Pd-II. The X-ray crystal structures of the [cis-1,2-cyclohexanediyl bis(diphenylphosphinite)]platinum dichloride, of the AMPP palladium complex from (1R,2S)-(-)-norephedrine and of the BAMP palladium complex [P,P'-diphenyl-1,2-cyclohexanediylbis(imino)bisphosphane]palladium dichloride have been determined. The chemical and optical stabilities Of many complexes in solution have been monitored by P-31 NMR spectroscopy. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.