683-72-7Relevant articles and documents
Investigation of binap-based hydroxyphosphine arene-ruthenium(II) complexes as catalysts for nitrile hydration
Toms-Mendivil, Eder,Menndez-Rodrguez, Luca,Francos, Javier,Crochet, Pascale,Cadierno, Victorio
, p. 63466 - 63474 (2015/02/19)
The binap-based hydroxyphosphine-(η6-arene)-ruthenium(ii) complexes [RuX{η6:κ1(P)-PPh2-binaphthyl}{PPh2(OH)}][OTf] (X = OTf (4), Cl (5)) have been evaluated as potential catalysts for the selective hydration of nitriles to primary amides. The triflate derivative 4 proved to be the most active, being able to hydrate a large variety of aromatic, heteroaromatic, α,β-unsaturated and aliphatic nitriles in pure water at 100°C. The utility of complex 4 to promote the catalytic rearrangement of aldoximes has also been demonstrated. In addition, insights about the role played by the hydroxyphosphine ligand PPh2(OH) during the catalytic reactions are given.
Thiazolyl-phosphine hydrochloride salts: Effective auxiliary ligands for ruthenium-catalyzed nitrile hydration reactions and related amide bond forming processes in water
Garcia-Alvarez, Rocio,Zablocka, Maria,Crochet, Pascale,Duhayon, Carine,Majoral, Jean-Pierre,Cadierno, Victorio
, p. 2447 - 2456 (2013/09/12)
A series of water-soluble N-protonated thiazolyl-phosphine hydrochloride salts have been synthesized and coordinated to the ruthenium(ii) fragment [RuCl2(η6-p-cymene)]. The resulting complexes were evaluated as potential catalysts for the selective hydration of nitriles to primary amides in environmentally friendly aqueous medium. The best results in terms of activity were achieved when tris(5-(2-aminothiazolyl))phosphine trihydrochloride was used as ligand. Using the Ru(ii) complex 9 derived from this salt (3 mol%), the catalytic reactions proceeded cleanly in pure water at 100 °C without the assistance of any additive, affording the desired amides in high yields (>78%) after short reaction periods (0.5-7 h). The process was operative with both aromatic, heteroaromatic, α,β-unsaturated and aliphatic nitriles, and tolerated several functional groups. The utility of 9 in promoting the formation of primary amides in water by catalytic rearrangement of aldoximes and direct coupling of aldehydes with NH2OH·HCl has also been demonstrated.
Ru(ii) complexes containing dmso and pyrazolyl ligands as catalysts for nitrile hydration in environmentally friendly media
Ferrer, íngrid,Rich, Jordi,Fontrodona, Xavier,Rodríguez, Montserrat,Romero, Isabel
, p. 13461 - 13469 (2013/09/23)
The synthesis of two Ru-dmso complexes containing the ligands 2-(3-pyrazolyl)pyridine (pypz-H), and pyrazole (pz-H), [RuIICl 2(pypz-H)(dmso)2], (2) and [RuIICl 2(pz-H)(dmso)3], (3), has been described. Both complexes have been fully characterized in solution through 1H-NMR and UV-Vis techniques and also in the solid state through monocrystal X-ray diffraction analysis. The redox properties of both complexes have also been studied by means of cyclic voltammetry. Exposure of 2 to visible light in acetonitrile produces a substitution of one dmso ligand by a solvent molecule generating a new complex, [RuIICl2(MeCN)(pypz-H)(dmso)] (4). Also, UV-visible spectroscopy points out that complex 2 presents a thermal and photochemical substitution of dmso ligands in aqueous solution. Finally, the reactivity of complexes 2 and 3 has been tested with regard to the hydration of nitriles using water as a single solvent, displaying good efficiency and selectivity for the corresponding amide derivatives. In general, better performance is achieved with complex 3. Reuse of these catalysts in water and glycerol has been explored for the first time in ruthenium-mediated nitrile hydration catalysis.
Efficient tandem process for the catalytic deprotection of N-allyl amides and lactams in aqueous media: A novel application of the bis(allyl)- ruthenium(IV) catalysts [Ru(η3:η2: η3-C12H18)Cl2] and [Ru(η3:η3-C10H16)-(μ-Cl) Cl}2]
Cadierno, Victorio,Gimeno, Jose,Nebra, Noel
, p. 6590 - 6594 (2008/03/13)
An operationally simple and highly efficient methodology for the removal of the allyl protecting group in amides and lactams has been developed by using the commercially available bis(allyl)-ruthenium(IV) catalysts [Ru(η3:η2:η3-C12H 18)Cl2] (C12H18 = dodeca-2,6,10-triene-1,12-diyl) and [(Ru(η3:η3- C10H16)(μ-Cl)Cl}2] (C10H 16 = 2,7-dimethylocta-2,6-diene-1,8-diyl). The tandem process, which takes place in aqueous media and proceeds in a one-pot manner, involves the initial isomerization of the C=C bond of the allyl unit and subsequent oxidative cleavage of the resulting enamide.
Interplay between the palladium(II) ion, unidentate ligands and hydroxyl groups from a bidentate ligand in a new complex that catalyses hydration and alcoholysis of nitrile and urea
Kaminskaia, Natalia V.,Guzei, Ilia A.,Kostic, Nenad M.
, p. 3879 - 3885 (2007/10/03)
Palladium(II) complexes containing the bidentate ligand 3,6-dithiaoctane-1,8-diol (dtod) and chloride anions (1) or solvent molecules (2) as two unidentate ligands were synthesized and characterized by 1H and 13C NMR spectroscopy. The complex 1, which is the precursor to the catalyst 2, was also characterized by elemental analysis and X-ray crystallography. The crystal structure of 1 shows square planar co-ordination of two sulfur and two chloride ligands to palladium(II), and also a hydrogen bonding network. The complex 2 catalyses hydration of dichloroacetonitrile to dichloroacetamide and methanolysis of dichloroacetonitrile to (dichloromethyl)methoxymethanimine. The catalysed reactions are as much as 106 times faster than the uncatalysed ones. The hydroxyl groups in the ligand dtod do not directly participate in the hydration and methanolysis reactions of dichloroacetonitrile catalysed by 2. The nitrile is activated for nucleophilic attack by its co-ordination to palladium(II). The nucleophile is the free water molecule or the aqua ligand in the hydration reaction and the free methanol molecule in the methanolysis reaction. Indeed, the latter reaction is first order with respect to methanol concentration. Urea and methylurea co-ordinated to palladium(II) in the complex 2 react with the hydroxyl groups of the dtod ligand and form alkyl carbamates. This unimolecular alcoholysis within the co-ordination sphere of palladium(II) is 240-380 times faster than the bimolecular alcoholysis involving external attack of free ethanol.
Nitrile Hydration catalysed by Palladium(II) Complexes
Kaminskaia, Natalia V.,Kostic, Nenad M.
, p. 3677 - 3686 (2007/10/03)
The palladium(II) complexes 2+, cis-2+, cis-2+, cis-2+ and 2+, which contain aquq, ethane-1,2-diamine (en), methionine methyl ester (Met-OMe), 1,5-dithiacyclooctan-3-ol (dtcol), and diethylenetriamine (dien) ligands, catalysed selective hydration of various nitriles, yielding the corresponding carboxamides.Further hydrolysis to carboxylic acids was not detected.The catalysed reactions are enhanced as much as 1E6-fold over the uncatalysed ones.Equilibrium constants for co-ordination of nitriles to palladium(II) complexes were determined or estimated.Since carboxamides do not detectably co-ordinate to palladium(II) in solutions containing water, the product of hydration does not inhibit the reaction.Carboxamidate anion, however, co-ordinates to palladium(II) in acetone solution.Kinetic effects of the following factors were examined: catalyst concentration, substrate concentratio, pD value, water concentration, electrophilicity of the nitrile group in the substrate, and electron donation and trans effect of the ancillary ligands in the catalyst.In the reaction catalysed by the four chelate complexes no intermediates were detected.In the hydration of CHCl2CN catalysed by 2+ palladium(II)-iminol complexes were observed as intermediates.In aqueous solutions only bidentate iminol coordination was detected.In acetone solutions the more labile unidentate iminol co-ordination was observed as well.The substrate (nitrile), the product (carboxamide), and an iminol intermediate were monitored in the cycle catalysed by 2+.This reaction was analysed in terms of the Michaelis-Menten model of enzyme kinetics, and microscopic rate constants were determined for the pathways involving and not involving the iminol intermediate.Internal attack on the nitrile ligand by the aqua (not hydroxide) ligand and external attack on the nitrile ligand by solvent water occur at similar rates.A general scheme of catalysis is devised on the basis of the kinetic experiments.
Metal radionuclide labeled proteins for diagnosis and therapy
-
, (2008/06/13)
Protein, ligand and anti-ligand conjugated chelated metal radionuclides are provided for use in vivo. Intermediates are provided for preparing the compositions efficiently.
Metal radionuclide labeled proteins for diagnosis and therapy
-
, (2008/06/13)
Protein conjugated chelated metal radionuclides are provided for use in vivo. Intermediates are provided for preparing the polypeptide compositions efficiently.
Metal radionuclide labeled proteins for diagnosis and therapy
-
, (2008/06/13)
Protein conjugated chelated metal radionuclides are provided for use in vivo. Intermediates are provided for preparing the polypeptide compositions efficiently.
