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1.
Cadierno V Crochet P García-Garrido SE Gimeno J 《Dalton transactions (Cambridge, England : 2003)》2004,(21):3635-3641
The novel water-soluble ruthenium(II) complexes [RuCl(2)(eta(6)-arene)[P(CH(2)OH)(3)]]2a-c and [RuCl(eta(6)-arene)[P(CH(2)OH)(3)](2)][Cl]3a-c have been prepared in high yields by reaction of dimers [[Ru(eta(6)-arene)(micro-Cl)Cl](2)](arene = C(6)H(6)1a, p-cymene 1b, C(6)Me(6)1c) with two or four equivalents of P(CH(2)OH)(3), respectively. Complexes 2/3a-c are active catalysts in the redox isomerization of several allylic alcohols into the corresponding saturated carbonyl compounds under water/n-heptane biphasic conditions. Among them, the neutral derivatives [RuCl(2)(eta(6)-C(6)H(6))[P(CH(2)OH)(3)]]2a and [RuCl(2)(eta(6)-p-cymene)[P(CH(2)OH)(3)]]2b show the highest activities (TOF values up to 600 h(-1); TON values up to 782). Complexes 2/3a-c also catalyze the hydration of terminal alkynes. 相似文献
2.
Cadierno V García-Garrido SE Gimeno J Nebra N 《Chemical communications (Cambridge, England)》2005,(32):4086-4088
A general and efficient method for the deprotection of N-allylic substrates in aqueous media, using catalytic amounts of the bis(allyl)-ruthenium(IV) complexes [Ru(eta3:eta2:eta3-C12H18)Cl2] and [{Ru(eta3:eta3-C10H16)(micro-Cl)Cl}2], has been developed. 相似文献
3.
Jeferson Rodrigo Souza Pina Joo Victor Silva-Silva Josiwander Miranda Carvalho Heriberto Rodrigues Bitencourt Luciano Almeida Watanabe Juan Matheus Pereira Fernandes Guilherme Eduardo de Souza Anna Caroline Campos Aguiar Rafael Victorio Carvalho Guido Fernando Almeida-Souza Ktia da Silva Calabrese Patrícia Santana Barbosa Marinho Andrey Moacir do Rosario Marinho 《Molecules (Basel, Switzerland)》2021,26(11)
The natural compound ravenelin was isolated from the biomass extracts of Exserohilum rostratum fungus, and its antimicrobial, antiplasmodial, and trypanocidal activities were evaluated. Ravenelin was isolated by column chromatography and HPLC and identified by NMR and MS. The susceptibility of Gram-positive and Gram-negative bacteria strains to ravenelin was determined by microbroth dilution assay. Cytotoxicity was evaluated in hepatocarcinoma cells (HepG2) and BALB/c peritoneal macrophages by using MTT. SYBR Green I-based assay was used in the asexual stages of Plasmodium falciparum. Trypanocidal activity was tested against the epimastigote and intracellular amastigote forms of Trypanosoma cruzi. Ravenelin was active against Gram-positive bacteria strains, with emphasis on Bacillus subtilis (MIC value of 7.5 µM). Ravenelin’s antiparasitic activities were assessed against both the epimastigote (IC50 value of 5 ± 1 µM) and the intracellular amastigote forms of T. cruzi (IC50 value of 9 ± 2 µM), as well as against P. falciparum (IC50 value of 3.4 ± 0.4 µM). Ravenelin showed low cytotoxic effects on both HepG2 (CC50 > 50 µM) and peritoneal macrophage (CC50 = 185 ± 1 µM) cells with attractive selectivity for the parasites (SI values > 15). These findings indicate that ravenelin is a natural compound with both antibacterial and antiparasitic activities, and considerable selectivity indexes. Therefore, ravenelin is an attractive candidate for hit-to-lead development. 相似文献
4.
Cadierno V Díez J García-Alvarez J Gimeno J 《Chemical communications (Cambridge, England)》2004,(16):1820-1821
The activation of 1,1-diphenyl-2-propyn-1-ol by complexes [RuCl(eta(6)-p-cymene)[eta(2)-P,N-Ph(2)PCH(2)P([=NR)Ph(2)]](+) results in the formation of the unusual tethered (eta(6)-arene)-ruthenium(ii) derivatives, via an unprecedented iminophosphorane-allenylidene coupling process. 相似文献
5.
Unmasking the Action of Phosphinous Acid Ligands in Nitrile Hydration Reactions Catalyzed by Arene–Ruthenium(II) Complexes
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Dr. Eder Tomás‐Mendivil Dr. Victorio Cadierno Dr. María I. Menéndez Dr. Ramón López 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(47):16874-16886
The catalytic hydration of benzonitrile and acetonitrile has been studied by employing different arene–ruthenium(II) complexes with phosphinous (PR2OH) and phosphorous acid (P(OR)2OH) ligands as catalysts. Marked differences in activity were found, depending on the nature of both the P‐donor and η6‐coordinated arene ligand. Faster transformations were always observed with the phosphinous acids. DFT computations unveiled the intriguing mechanism of acetonitrile hydration catalyzed by these arene–ruthenium(II) complexes. The process starts with attack on the nitrile carbon atom of the hydroxyl group of the P‐donor ligand instead of on a solvent water molecule, as previously suggested. The experimental results presented herein for acetonitrile and benzonitrile hydration catalyzed by different arene–ruthenium(II) complexes could be rationalized in terms of such a mechanism. 相似文献
6.
Varela-Álvarez A Sordo JA Piedra E Nebra N Cadierno V Gimeno J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(38):10583-10599
A general mechanism to rationalize Ru(IV) -catalyzed isomerization of the C=C bond in O-allylic substrates is proposed. Calculations supporting the proposed mechanism were performed at the MPWB1K/6-311+G(d,p)+SDD level of theory. All experimental observations in different solvents (water and THF) and under different pH conditions (neutral and basic) can be interpreted in terms of the new mechanism. Theoretical analysis of the transformation from precatalyst to catalyst led to structural identification of the active species in different media. The experimentally observed induction period is related to the magnitudes of the energy barriers computed for that process. The theoretical energy profile for the catalytic cycle requires application of relatively high temperatures, as is experimentally observed. Participation of a water molecule in the reaction coordinate is mechanistically essential when the reaction is carried out in aqueous medium. The new mechanistic proposal helped to develop a new experimental procedure for isomerization of allyl ethers to 1-propenyl ethers under neutral aqueous conditions. This process is an unique example of efficient and selective catalytic isomerization of allyl ethers in aqueous medium. 相似文献
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8.
Cardoso CL de Moraes MC Guido RV Oliva G Andricopulo AD Wainer IW Cass QB 《The Analyst》2008,133(1):93-99
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) plays an important role in the life cycle of the Trypanosoma cruzi, and an immobilized enzyme reactor (IMER) has been developed for use in the on-line screening for GAPDH inhibitors. An IMER containing human GAPDH has been previously reported; however, these conditions produced a T. cruzi GAPDH-IMER with poor activity and stability. The factors affecting the stability of the human and T. cruzi GAPDHs in the immobilization process and the influence of pH and buffer type on the stability and activity of the IMERs have been investigated. The resulting T. cruzi GAPDH-IMER was coupled to an analytical octyl column, which was used to achieve chromatographic separation of NAD(+) from NADH. The production of NADH stimulated by d-glyceraldehyde-3-phosphate was used to investigate the activity and kinetic parameters of the immobilized T. cruzi GAPDH. The Michaelis-Menten constant (K(m)) values determined for d-glyceraldehyde-3-phosphate and NAD(+) were K(m) = 0.5 +/- 0.05 mM and 0.648 +/- 0.08 mM, respectively, which were consistent with the values obtained using the non-immobilized enzyme. 相似文献
9.
A general and efficient procedure for the stereoselective synthesis of (E)-(1-propenyl)phenyl esters from readily accessible allylphenols has been developed. The process involves a two-step sequence consisting of the initial acylation of the allylphenols with an acid chloride, followed by catalytic CC bond isomerization in the resulting allylphenyl esters. The latter step was performed in methanol at 80 °C using catalytic amounts (0.5 mol %) of the commercially available bis(allyl)-ruthenium(IV) dimer [{RuCl(μ-Cl)(η3:η3-C10H16)}2] (C10H16=2,7-dimethylocta-2,6-diene-1,8-diyl). Reactions proceeded in high yields (68–93%) and short times (4–9 h) with complete E-selectivity. 相似文献
10.
Cadierno V Zablocka M Donnadieu B Igau A Majoral JP Skowronska A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(2):345-352
Polycyclic zwitterionic complexes that incorporate one or two phosphonium unit(s) as cationic center(s) and zirconocene-ate moiety(ies) as the anionic counterpart(s) can be easily prepared by either [1+3] or [1+3] and [2+3] cycloadditions which involve bi- or tricyclic alpha-zirconated phosphanes 3 or 4 and various azides. Some of these species exhibit unprecedented phosphazide chelation with bonding between the zirconium and a nitrogen atom in the alpha position relative to phosphorus. When heated, the phosphazide complexes lose dinitrogen to form stable polycyclic zwitterionic phosphonium mono- or dinuclear complexes. The solid-state structure of the two zwitterionic complexes 5 and 8 was determined by X-ray crystallography. 相似文献