12107-56-1Relevant academic research and scientific papers
Synthesis, characterization and application of pure and decorated with palladium mesoporous cobalt hydroxide hexagonal nanorings
Díaz-García, Diana,Darbandi, Masih,Gómez-Ruiz, Santiago,Narimani, Ehsan
, (2020)
For most of the catalytic reactions dealing with noble metals, a replacement of pure noble metals with hybrid noble metal-nanomaterials or nanocomposites is a well-stablished strategy for reducing the cost of the catalytic process. The application of this strategy is challenging and of interest for the scientific community. In this context, we report the design of Pd-anchored mesoporous cobalt hydroxide nanoring composites which, used as catalysts, can efficiently catalyze Suzuki C–C coupling reactions with excellent activity, versatility and selectivity due to the strong synergetic effect standing from its structure and composition. Hybrid systems based on mesoporous Co(OH)2 nanoparticles and Pd are able to reach up to 88percent conversion of iodobenzene and 37percent yield of the biphenyl product at 24 h. Additionally, the photocatalytic performance of the hybrid system has been investigated in selective oxidation of benzylalcohol and organic dye degradation. This nanostructured material was able to selectively photo-oxidize benzyl alcohol to benzaldehyde under LED light with moderate catalytic activity (turnover numbers and turnover frequencies were of 4.62 and 0.78 h?1 respectively with 95percent selectivity). In addition, the studied hybrid system was able to degrade methylene blue in water with good performance via a photocatalytic reaction by irradiation with UV light and LED light (the kinetic constant for a first order degradation was 1.03·10?4 s?1 and 1.24·10?5 s?1, respectively). Thus, our preliminary catalytic results show that these nanomaterials, based on Co(OH)2 nanoparticles with low content of noble-metal, are promising candidates for their potential use in different industrial catalytic applications.
Dual application of Pd nanoparticles supported on mesoporous silica SBA-15 and MSU-2: Supported catalysts for C-C coupling reactions and cytotoxic agents against human cancer cell lines
Balbn, Adriana,Gaballo, Francesco,Ceballos-Torres, Jess,Prashar, Sanjiv,Fajardo, Mariano,Kaluderovi, Goran N.,Gmez-Ruiz, Santiago
, p. 54775 - 54787 (2014)
Two different mesoporous silica-based materials (SBA-15 and MSU-2) have been treated under mild conditions with different quantities of [PdCl2(cod)] (cod = 1,5-cyclooctadiene) to promote the formation of supported palladium nanoparticles (materials of the type SBA-15-Pd and MSU-2-Pd). The synthesized materials have been characterized by different techniques observing that the palladium nanoparticles remain impregnated in the silica. The catalytic activity of the hybrid Pd-silica materials has been tested in Suzuki-Miyaura C-C coupling reactions observing moderate conversion rates in the reactions of 3-bromoanisole with 4-carboxyphenylboronic acid and 2-bromopyridine with 4-carboxyphenylboronic acid. In addition, the synthesized materials showed a good degree of recyclability, being catalytically active in five consecutive catalytic tests. Finally, in order to evaluate the cytotoxicity of the synthesized materials, in vitro tests against five different human cancer cell lines have been carried out, observing high cytotoxic activities of the hybrid systems comparable if not somewhat higher to other systems based on metal complexes supported on mesoporous silicas described previously in the literature. To the best of our knowledge the cytotoxic study reported here represents the first evaluation of the anticancer action of supported palladium nanoparticles in human cancer cells.
Pd-catalyzed Sonogashira coupling in aqueous media. Observation of micelles that contain substrates and catalyst
Suzaki, Yuji,Kobayashi, Yuka,Tsuchido, Yoshitaka,Osakada, Kohtaro
, p. 106 - 111 (2019)
Sonogashira-coupling of 4-iodoanisole with 4-methylphenylacetylene was conducted in the presence of Pd(II) catalyst, NEt3, CuI and sodium dodecylsulfonate (SDS) in aqueous media. The reaction catalyzed by PdCl2(Me2NCH2CH2NMe2) (2b) at 80 °C affords 4-methoxyphenyl-4′-methylphenylalkyne in 51% yield after 2.0 h, whereas those catalyzed by the complexes with other ethylenediamine derivatives, PdCl2(R2NCH2CH2NR2) (R[dbnd]H, C2H5, C3H7, C4H9, and C6H13), formed the product in lower yields (18–26%). Aqueous solution of complex 2b (5.3 mM) and SDS (168 mM) forms a yellow colloidal solution, which is stable for one night at room temperature. The complexes of ethylenediamines with higher alkyl substituents on the nitrogen atoms do not form apparently homogeneous solutions. TEM (transmission electron micrograph) observation of the former solution ([2b] = 5.3 mM), layered on a copper grid surface, revealed formation of Pd-containing micelles with diameters of ca. 4.0–6.0 nm A mixture of 2b (5.4 mM), 4-iodoanisole (125 mM) and 4-methylphenyl acetylene (250 mM) in water contains micelles with diameters smaller than 40 nm, as is clearly observed by TEM. Mixtures of the other complexes and the substrates contain micelles with larger sizes, and their TEM images are obscure. Thus, complex 2b forms small and clear micelles containing the catalyst and the substrate in the reaction mixture, and the micelle formation enhances the reaction in aqueous media.
Synthesis and study of the catalytic applications in C–C coupling reactions of hybrid nanosystems based on alumina and palladium nanoparticles
Hossain, Abul Monsur Showkot,Balbín, Adriana,Erami, Roghayeh Sadeghi,Prashar, Sanjiv,Fajardo, Mariano,Gómez-Ruiz, Santiago
, p. 645 - 652 (2017)
Nanostructured alumina has been treated under mild conditions with different quantities of [PdCl2(cod)] (cod = 1,5-cyclooctadiene) to promote the formation of supported palladium nanoparticles which have been characterized by XRD, XRF, BET and TEM. The results show that the new hybrid materials, nano-Al2O3-Pd-20 and nano-Al2O3-Pd-50, consist of impregnated palladium nanoparticles onto aggregates of nanoparticles of alumina. The catalytic activity of the hybrid Pd-alumina materials has been tested in Suzuki–Miyaura C–C coupling reactions observing good conversion rates in the reactions of 3-bromoanisole with 4-carboxyphenylboronic acid or 4-vinylphenylboronic acid. The catalytic studies have been extended with experiments investigating the Pd loading influence. Catalyst recyclability tests show a slight decrease in activity after the first cycle in the reaction of 3-bromoanisole with 4-vinylphenylboronic acid. However, subsequent activity remains almost constant after five more consecutive catalytic cycles.
Method for in-situ preparation of (1, 5-cyclooctadiene) palladium dichloride
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Paragraph 0043-0062, (2022/03/27)
The invention relates to a method for in-situ preparation of (1, 5-cyclooctadiene) palladium dichloride, and belongs to the technical field of preparation of noble metal homogeneous catalysts. According to the (1, 5-cyclooctadiene) palladium dichloride prepared by the in-situ method disclosed by the invention, the raw material is palladium powder, and the cost of the raw material is relatively low. Solvents and medicines used in the preparation process are conventional acid-base and alcohol solvents, so that the toxicity is low, the price is low, and the method is suitable for industrial large-scale production. Meanwhile, by adding the complexing accelerant, the use amount of the ligand 1, 5-cyclooctadiene can be effectively reduced, the cost is reduced, and meanwhile, the green and environment-friendly requirements are better met. In addition, high-temperature heating is not needed in the preparation process, reaction conditions are easy to achieve, steps are simple and convenient, the product yield is high, washing is easy, and multiple synthesis steps are directly prepared through a one-pot series connection method. And the product has the characteristics of low metal impurity content and the like, meets the use requirements of the homogeneous catalyst, and is suitable for being used as the homogeneous catalyst in the organic synthesis reaction of various medicines and fine chemical products.
A Neophyl Palladacycle as an Air- And Thermally Stable Precursor to Oxidative Addition Complexes
Buchwald, Stephen L.,King, Ryan P.,Krska, Shane W.
supporting information, p. 7927 - 7932 (2021/10/25)
The utilization of isolated Palladium Oxidative Addition Complexes (OACs) has had a significant impact on Pd-catalyzed and Pd-mediated cross-coupling reactions. Despite their importance, widespread utility of OACs has been limited by the instability of their precursor complexes. Herein, we report the use of Cámpora's palladacycle as a new, more stable precursor to Pd OACs. Using this palladacycle, a series of biarylphosphine ligated OACs, including those with pharmaceutical-derived aryl halides and relevance to bioconjugation, were prepared.
CNN Coordination Accelerates the iClick Reaction of Square-Planar Palladium(II) and Platinum(II) Azido Complexes with Electron-Poor Alkynes and Enables Cycloaddition with Terminal Alkynes
Moreth, Dominik,Peng, Kun,Schatzschneider, Ulrich
supporting information, p. 2584 - 2593 (2021/08/20)
Organometal azido complexes with a cyclometalating C^N^N coligand of the general formula [M(N3)(phbpy)] with M = Pd(II) or Pt(II) and Hphbpy = 6-phenyl-2,2′-bipyridine were prepared in very good yield and reacted in a catalyst-free iClick reaction with internal alkynes 4,4,4-trifluoro-2-butynoic acid ethyl ester and dimethyl acetylenedicarboxylate and also methyl propiolate as a prototypical terminal alkyne. At room temperature, the two internal alkynes reacted too fast to study the kinetics with NMR spectroscopy, as the first spectrum obtained after mixing of the reactants showed only the product. Only in the case of methyl propiolate, second-order rate constants were obtained as 7.7 × 10-3 and 5.6 × 10-3 M-1 s-1 for the Pd(II) and Pt(II) azido complexes, respectively. As an alternative method with a shorter lag time, solution IR spectroscopy monitoring the disappearance of the azido vibration was used to obtain pseudo-first-order rate constants in the range of 3-4 × 10-4 s-1 for the terminal alkyne and 10-2 s-1 for the internal alkynes, with a general trend in the reactivity of Pd > Pt and CF3,COOEt > COOCH3,COOCH3 ? H,COOCH3.
Platinum Cyclooctadiene Complexes with Activity against Gram-positive Bacteria
Frei, Angelo,Ramu, Soumya,Lowe, Gabrielle J.,Dinh, Hue,Semenec, Lucie,Elliott, Alysha G.,Zuegg, Johannes,Deckers, Anke,Jung, Nicole,Br?se, Stefan,Cain, Amy K.,Blaskovich, Mark A. T.
supporting information, p. 3165 - 3171 (2021/07/16)
Antimicrobial resistance is a looming health crisis, and it is becoming increasingly clear that organic chemistry alone is not sufficient to continue to provide the world with novel and effective antibiotics. Recently there has been an increased number of reports describing promising antimicrobial properties of metal-containing compounds. Platinum complexes are well known in the field of inorganic medicinal chemistry for their tremendous success as anticancer agents. Here we report on the promising antibacterial properties of platinum cyclooctadiene (COD) complexes. Amongst the 15 compounds studied, the simplest compounds Pt(COD)X2 (X=Cl, I, Pt1 and Pt2) showed excellent activity against a panel of Gram-positive bacteria including vancomycin and methicillin resistant Staphylococcus aureus. Additionally, the lead compounds show no toxicity against mammalian cells or haemolytic properties at the highest tested concentrations, indicating that the observed activity is specific against bacteria. Finally, these compounds showed no toxicity against Galleria mellonella at the highest measured concentrations. However, preliminary efficacy studies in the same animal model found no decrease in bacterial load upon treatment with Pt1 and Pt2. Serum exchange studies suggest that these compounds exhibit high serum binding which reduces their bioavailability in vivo, mandating alternative administration routes such as e. g. topical application.
Palladium-Catalyzed Synthesis of α-Carbonyl-α′-(hetero)aryl Sulfoxonium Ylides: Scope and Insight into the Mechanism
Janot, Christopher,Chagnoleau, Jean-Baptiste,Halcovitch, Nathan R.,Muir, James,A?ssa, Christophe
, p. 1126 - 1137 (2019/12/30)
Despite recent advances, a general method for the synthesis of α-carbonyl-α′-(hetero)aryl sulfoxonium ylides is needed to benefit more greatly from the potential safety advantages offered by these compounds over the parent diazo compounds. Herein, we report the palladium-catalyzed cross-coupling of aryl bromides and triflates with α-carbonyl sulfoxonium ylides. We also report the use of this method for the modification of an active pharmaceutical ingredient and for the synthesis of a key precursor of antagonists of the neurokinin-1 receptor. In addition, the mechanism of the reaction was inferred from several observations. Thus, the oxidative addition complex [(XPhos)PhPdBr] and its dimer were observed by 31P{1H} NMR, and these complexes were shown to be catalytically and kinetically competent. Moreover, a complex resulting from the transmetalation of [(XPhos)ArPdBr] (Ar = p-CF3-C6H4) with a model sulfoxonium ylide was observed by mass spectrometry. Finally, the partial rate law suggests that the transmetalation and the subsequent deprotonation are rate-determining in the catalytic cycle.
IClick Reactions of Square-Planar Palladium(II) and Platinum(II) Azido Complexes with Electron-Poor Alkynes: Metal-Dependent Preference for N1 vs N2 Triazolate Coordination and Kinetic Studies with 1H and 19F NMR Spectroscopy
Peng, Kun,Mawamba, Viviane,Schulz, Ellina,L?hr, Mario,Hagemann, Carsten,Schatzschneider, Ulrich
supporting information, p. 11508 - 11521 (2019/08/26)
Two square-planar palladium(II) and platinum(II) azido complexes [M(N3)(L)] with L = N-phenyl-2-[1-(2-pyridinyl)ethylidene]hydrazine carbothioamide reacted with four different electron-poor alkynes R-CC-R′ with R = R′ = COOCH3, COOEt, COOCH2CH2OCH3 or R = CF3, R′' = COOEt in a [3 + 2] cycloaddition "iClick" reaction. The resulting triazolate complexes [M(triazolateR,R')(L)] were isolated by simple precipitation and/or washing in high purity and good yield. Six out of the eight new compounds feature the triazolate ligand coordinated to the metal center via the N2 nitrogen atom, but fortuitous solubility properties allowed isolation of the N1 isomer in two cases from acetone. When the solvent was changed to DMSO, the N1 → N2 isomerization could be studied by NMR spectroscopy and took several days to complete. 19F NMR studies of the iClick reaction with F3C-CC-COOEt led to identification of a putative early linear intermediate in addition to the N1 and N2 isomers, however with the latter as the final product. Rate constants determined by 1H or 19F NMR spectroscopy increased in the order Pd > Pt and CF3/COOEt > COOR/COOR with R = CH3, Et, CH2CH2OCH3. The second-order rate constant k2 > 3.7 M-1 s-1 determined for the reaction of [Pd(N3)(L)] with F3C-CC-COOEt is the fastest observed for an iClick reaction so far and compares favorably with that of the most evolved strained alkynes reported for the SPAAC (strain-promoted azide-alkyne cycloaddition) to date. Selected title compounds were evaluated for their anticancer activity on the GaMG human glioblastoma brain cancer cell line and gave EC50 values in the low micromolar range (2-16 μM). The potency of the Pd(II) complexes increased with the chain length of the substituents in the 4- and 5-positions of the triazolate ligand.
