1113-58-2Relevant articles and documents
Bis(allyl)-ruthenium(IV) complexes with phosphinous acid ligands as catalysts for nitrile hydration reactions
Tomás-Mendivil, Eder,Francos, Javier,González-Fernández, Rebeca,González-Liste, Pedro J.,Borge, Javier,Cadierno, Victorio
, p. 13590 - 13603 (2016)
Several mononuclear ruthenium(iv) complexes with phosphinous acid ligands [RuCl2(η3:η3-C10H16)(PR2OH)] have been synthesized (78-86% yield) by treatment of the dimeric precursor [{RuCl(μ-Cl)(η3:η3-C10H16)}2] (C10H16 = 2,7-dimethylocta-2,6-diene-1,8-diyl) with 2 equivalents of different aromatic, heteroaromatic and aliphatic secondary phosphine oxides R2P(O)H. The compounds [RuCl2(η3:η3-C10H16)(PR2OH)] could also be prepared, in similar yields, by hydrolysis of the P-Cl bond in the corresponding chlorophosphine-Ru(iv) derivatives [RuCl2(η3:η3-C10H16)(PR2Cl)]. In addition to NMR and IR data, the X-ray crystal structures of representative examples are discussed. Moreover, the catalytic behaviour of complexes [RuCl2(η3:η3-C10H16)(PR2OH)] has been investigated for the selective hydration of organonitriles in water. The best results were achieved with the complex [RuCl2(η3:η3-C10H16)(PMe2OH)], which proved to be active under mild conditions (60 °C), with low metal loadings (1 mol%), and showing good functional group tolerance.
Synthesis of aliphatic (S)-α-hydroxycarboxylic amides using a one-pot bienzymatic cascade of immobilised oxynitrilase and nitrile hydratase
Van Pelt, Sander,Van Rantwijk, Fred,Sheldon, Roger A.
, p. 397 - 404 (2009)
A one-pot bienzymatic cascade combining a hydroxynitrile lyase (Manihot esculenta, E.C. 4.1.2.10) and a nitrile hydratase (Nitriliruptor alkaliphilus, E.C. 4.2.1.84) for the synthesis of enantiopure aliphatic α- hydroxycarboxylic amides from aldehydes is described. Both enzymes were immobilised as cross-linked enzyme aggregates (CLEAs). Stability tests show that the nitrile hydratase CLEAs are sensitive to water-immiscible organic solvents as well as to aldehydes and hydrogen cyanide (HCN), but are remarkably stable and show useful activity in acidic aqueous environments of pH 4-5. The cascade reactions are consequently carried out by using a portionwise feed of HCN and moderate concentrations of aldehyde in acidic aqueous buffer to suppress the uncatalysed hydrocyanation background reaction. After optimisation, this method was used to synthesise five different kinds of aliphatic α- hydroxycarboxylic amides from the corresponding aldehydes with good yields and with enantiomeric purities comparable to those obtained for the α-hydroxynitriles in the microaqueous hydrocyanation using hydroxynitrile lyase and an excess of HCN.
Photoiodocarboxylation of Activated C=C Double Bonds with CO2 and Lithium Iodide
Mello, Rossella,Arango-Daza, Juan Camilo,Varea, Teresa,González-Nú?ez, María Elena
, p. 13381 - 13394 (2018/11/20)
The photolysis at 254 nm of lithium iodide and olefins 1 carrying an electron-withdrawing Z-substituent in CO2-saturated (1 bar) anhydrous acetonitrile at room temperature produces the atom efficient and transition metal-free photoiodocarboxylation of the C=C double bond. The reaction proceeds well for terminal olefins 1 to form the new C-I and C-C σ-bonds at the α and β-positions of the Z-substituent, respectively, and is strongly inhibited by polar protic solvents or additives. The experimental results suggest that the reaction channels through the radical anion [CO2?-] in acetonitrile, yet involves different intermediates in aqueous medium. The stabilizing ion-quadrupole and electron donor-acceptor interactions of CO2 with the iodide anion play a crucial role in the reaction course as they allow CO2 to penetrate the solvation shell of the anion in acetonitrile, but not in water. The reaction paths and the reactive intermediates involved under different conditions are discussed.
An efficient ruthenium(iv) catalyst for the selective hydration of nitriles to amides in water under mild conditions
Tomás-Mendivil, Eder,Suárez, Francisco J.,Díez, Josefina,Cadierno, Victorio
supporting information, p. 9661 - 9664 (2014/08/18)
A Ru(iv) catalyst able to promote the selective hydration of nitriles to amides in water, at low metal loadings and under mild conditions, is presented. This journal is the Partner Organisations 2014.
