Palladium(II) and platinum(II) complexes containing new phosphinoxy chiral P,N-ligands

• Published in: Inorganica Chimica Acta Vol. 277; no. 1; pp. 119 - 126
• Main Authors: Franciò, Giancarlo, Arena, Carmela Grazia, Panzalorto, Manuela, Bruno, Giuseppe, Faraone, Felice
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.07.1998
• Subjects: Chiral P,N-ligand complexes; Crystal structures; Palladium complexes; Platinum complexes; Chiral P,N-ligand complexes; Crystal structures; Palladium complexes; Platinum complexes
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/S0020-1693(97)06085-4

The chiral diphenylphosphinoxy P,N-ligands (+)-(2 S,3 R)-4-dimethylamino-3-methyl-1,2-diphenyl-2-diphenylphophinoxybutane ( 2) and (+)-(1 S,2 R)-2-dimethyl-amino-1-phenyl-1-diphenylphosphinoxy-propane ( 3) have been prepared starting from the corresponding aminoalcohols. The reactions of the already reported ligand 2[1-phosphinoxy-1-(1 S,2 S,5 R)-menthyl]pyridine ( 1) and of 2 and 3 with palladium(II) and platinum(II) substrates have been studied. The palladium complexes [Pd( 1–3)Cl 2] have been used as catalytic precursors in the asymmetric Grignard cross-coupling reaction between 1-phenylethyl magnesium bromide and vinyl bromide. Some considerations on the low enantioselectivity found using the phosphinoxy P,N-ligands 1–3 are proposed. With the aim of verifying diastereoselectivity in the nucleophilic substitution reactions at palladium(II) and platinum(II) complexes containing the P,N-ligands 1–3, the reactions of the complexes 5, 6, 7 and 10 with the Grignard reagent PhMeCHMgBr, in the racemic form, have been unsuccessfully undertaken. The X-ray crystal structures of [Pt( 3)(Ph 2PO)Cl], 10, and of the oxide of 1 are also reported.