Bis(allyl)-ruthenium(iv) complexes with phosphinous acid ligands as catalysts for nitrile hydration reactions. Issue 34 (11th August 2016) - Tomás-Mendivil, Eder
Abstract : The preparation of bis(allyl)-Ru(iv ) complexes with phosphinous acid ligands is presented, as well as their application as catalysts in the base-free hydration of organonitriles in water. Abstract : Several mononuclear ruthenium(iv ) complexes with phosphinous acid ligands [RuCl2 (η 3 :η 3 -C10 H16 )(PR2 OH)] have been synthesized (78–86% yield) by treatment of the dimeric precursor [{RuCl(μ-Cl)(η 3 :η 3 -C10 H16 )}2 ] (C10 H16 = 2, 7-dimethylocta-2, 6-diene-1, 8-diyl) with 2 equivalents of different aromatic, heteroaromatic and aliphatic secondary phosphine oxides R2 P(O)H. The compounds [RuCl2 (η 3 :η 3 -C10 H16 )(PR2 OH)] could also be prepared, in similar yields, by hydrolysis of the P–Cl bond in the corresponding chlorophosphine–Ru(iv ) derivatives [RuCl2 (η 3 :η 3 -C10 H16 )(PR2 Cl)]. In addition to NMR and IR data, the X-ray crystal structures of representative examples are discussed. Moreover, the catalytic behaviour of complexes [RuCl2 (η 3 :η 3 -C10 H16 )(PR2 OH)] has been investigated for the selective hydration of organonitriles in water. The best results were achieved with the complex [RuCl2 (η 3 :η 3 -C10 H16 )(PMe2 OH)], which proved to be active under mild conditions (60 °C), with low metal loadings (1 mol%), and showing good functional group tolerance.