Isolation of enantiomerically pure organometallic palladium compounds: synthesis of the triangles prepared from enantiopure [cis-Pd2(C6H4PPh2)2(NCCH3)4]2

• Published in: Dalton transactions : an international journal of inorganic chemistry 2009-04 (16), p.2993-2998
• Main Authors: Koshevoy, Igor O, Gutierrez-Puebla, Enrique, Lahuerta, Pascual, Monge, Angeles, Ubeda, M Angeles, Sanaú, Mercedes
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/b816803b

Reaction of the racemic [Pd(C(6)H(4)PPh(2))Br](4) () with the silver salt of 1R-(1alpha,2beta,3alpha)]-3-methyl-2-(nitromethyl)-5-oxocyclopentaneacetate, (R)-AgO(2)CR*, results in the formation of a mixture of diastereoisomers (RRR)- and (SRR)- of the formula Pd(2)(C(6)H(4)PPh(2))(2)(O(2)CR*)(2) that were separated by standard chromatographic methods. Each diastereoisomer was readily converted into the tetrametallic stereoisomers (SS)- and (RR)-, of the formula [Pd(C(6)H(4)PPh(2))Br](4) that were isolated and characterized by X-ray crystallography. The R enantiomer of the solvated cationic species [cis-Pd(2)(C(6)H(4)PPh(2))(2)(NCCH(3))(4)](2+), obtained from (RR)-, was reacted with ammonium terephthalate yielding RRR-[Pd(2)(C(6)H(4)PPh(2))(2)](3)(O(2)CC(6)H(4)CO(2))(3), (RRR)-. The reaction of ammonium diphenyldicarboxylate with the S enantiomer of the solvated species, gave SSS-[Pd(2)(C(6)H(4)PPh(2))(2)](3)(O(2)CC(6)H(4)C(6)H(4)CO(2))(3), (SSS)-. Compounds and have been crystallographically characterized. Reactions performed with racemic [Pd(2)(C(6)H(4)PPh(2))(2)(CH(3)CN)(4)](2+), have also been studied and the relative chiralities of the triangles have been determined by (31)P NMR spectroscopy.