2-(1-(Dimethylamino)ethyl)phenylpalladium(II) complexes 5-functionalized with fluorous silyl tails

• Published in: Inorganica Chimica Acta 2006-06, Vol.359 (9), p.2674-2682
• Main Authors: Kleijn, Henk, Kleij, Arjan W., de Pater, Jeroen J.M., Lutz, Martin, Spek, Anthony L., Jastrzebski, Johann T.B.H., Deelman, Berth-Jan, van Koten, Gerard
• Format: Article
• Language: English
• Subjects: C, N-Chelating ligand; Cyclo-metallation; FBS; Fluorophilicity; Fluorous biphasic separation; Partition coefficient; Pd(II); α-Methyl- N, N-dimethylbenzylamine
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2005.10.056

Fluorous palladium complexes based on the chiral ligand α-methyl- N, N-dimethylbenzylamine (TMBA) are described. Cyclo-palladation by treatment with Pd(OAc) 2/LiCl gave the dimeric arylpalladium(II) complexes, which were converted into monomeric adducts by complexation with pyridine or triphenylphosphine. The fluorophilicty of the different compounds as determined in perfluoromethylcyclohexane/ n-octane as well as the crystal molecular structure of the triphenylphosphine complex are discussed. New fluorous-organometallics based on the chiral ligand α-methyl- N, N-dimethylbenzylamine (TMBA) were prepared by treatment of fluorous silyl bromide reagents with in situ 4-lithiated TMBA to give fluorous N, N-dimethyl(α-methyl-4-trialkylsilylbenzyl)amine ligands 1a– 1c that vary in the number of fluorous tails attached to the Si atom. Ligands 1a– 1c were successfully cyclo-palladated by treatment with Pd(OAc) 2/LiCl in methanol to furnish the corresponding chloride-bridged dimeric arylpalladium(II) complexes 2a– 2c in good yields. The latter derivatives could be converted into monomeric Lewis-base adducts by complexation with pyridine ( 3a– 3c), or triphenylphosphine ( 4a– 4c). The crystal structure of triphenylphosphine complex 4a has been elucidated. To probe their fluorophilicity, the partition coefficient of each of the derivatives in the fluorous biphasic solvent (FBS) system perfluoromethylcyclohexane/ n-octane has been determined.