588-59-0Relevant articles and documents
Carbonyl Coupling on the TiO2(001) Surface
Idriss, H.,Pierce, K.,Barteau, M. A.
, p. 715 - 716 (1991)
-
Controllable synthesis of palladium nanoparticles and their catalytic abilities in Heck and Suzuki reactions
Li, Yong,Dai, Yu,Yang, Zhengyin,Li, Tianrong
, p. 59 - 62 (2014)
The monodisperse palladium nanoparticles with the size of about 5.0 nm were prepared by the thermal decomposition of palladium acetylacetonate in the presence of oleylamine and borane tributylamine complex. The palladium nanoparticles were loaded on the a
Influence of the Support on the Catalytic Characteristics of the Deposited Palladium in the Liquid-Phase Hydrogenation of Diphenylacetylene
Bragina,Smirnova,Krivoruchenko,Markov,Baeva,Stakheev, A. Yu.
, p. 763 - 770 (2017)
Palladium catalysts on various types of supports were studied in the liquid-phase hydrogenation of diphenylacetylene. Samples of Pd/SiO2–Al2O3, Pd/MgAl2O4, Pd/Al2O3, and Pd/TiO2 were characterized by the chemisorption of the CO and IR spectroscopy of adsorbed CO. The use of n-hexane as the solvent increases the reaction rate, which can be explained by the better solubility of hydrogen in the liquid phase. It is established that the acid–base properties of the support do not affect the activity and selectivity of the catalysts in the reaction under study. However, they alter the electronic state of palladium. According to the catalytic tests, Pd/TiO2 has the highest activity (turnover frequency) and selectivity to alkene. The comparison of the obtained catalytic data and the results of IR spectroscopy made it possible to conclude that this is due to the electron density redistribution between the palladium and TiOx particles, which is caused by the strong metal–support interaction.
THE PETERSON REACTION, PART I, THE EFFECT OF REACTION CONDITIONS AND STERIC CROWDING
Bassindale, Alan R.,Ellis, Richard J.,Taylor, Peter G.
, p. 2705 - 2708 (1984)
The diastereoisomeric ratio of stilbenes formed in the Peterson reaction of PhCHSiR3(-) with PhCHO is shown to be insensitive to medium effects and temperature, but varies significantly as the bulk of SiR3 increases.
Akhrem et al.
, (1972)
Isolated, well-defined organovanadium(III) on silica: Single-site catalyst for hydrogenation of alkenes and alkynes
Sohn,Camacho-Bunquin,Langeslay,Ignacio-De Leon,Niklas,Poluektov,Liu,Connell,Yang,Kropf,Kim,Stair,Ferrandon,Delferro
, p. 7325 - 7328 (2017)
A well-defined, isolated, single-site organovanadium(iii) catalyst on SiO2 [(SiO2)V(Mes)(THF)] was synthesized via surface organometallic chemistry, and fully characterized using a combination of analytical and spectroscopic techniques (EA, ICP, 1H NMR, TGA-MS, EPR, XPS, DR-UV/Vis, UV-Raman, DRIFTS, XAS). The catalyst exhibits unprecedented reactivity in liquid-and gas-phase alkene/alkyne hydrogenation. Kinetic poisoning experiments revealed that 100% of the V sites are active for hydrogenation.
Catalytic investigations of carbon-carbon bond-forming reactions by a hydroxyapatite-bound palladium complex
Mori, Kohsuke,Hara, Takayoshi,Oshiba, Michitaka,Mizugaki, Tomoo,Ebitani, Kohki,Kaneda, Kiyotomi
, p. 1174 - 1181 (2005)
A new type of hydroxyapatite-bound palladium complex (PdHAP-1) was synthesized by treatment of a nonstoichiometric Ca-deficient hydroxyapatite, Ca9(HPO4)(PO4)5(OH), with PdCl 2(PhCN)2 in ac
Stable functionalized phosphorenes with photocatalytic HER activity
Vishnoi, Pratap,Gupta, Uttam,Pandey, Richa,Rao
, p. 6631 - 6637 (2019)
Phosphorene, a mono-elemental 2D material of phosphorus, can catalyze the hydrogen evolution reaction (HER) owing to the suitable position of its conduction band minimum but the ambient instability of phosphorene is the major challenge for its application. We have functionalized phosphorene with indium(iii) chloride, tris(pentafluorophenyl) borane and a benzyl group. The functionalized phosphorenes show stability under ambient conditions as well as good dispersibility in water and exhibit hydrogen yields as high as 6597 μmol h-1 g-1. The HER activity of the functionalized phosphorenes is much superior compared to pristine phosphorene and black phosphorus-based catalysts reported earlier.
Adsorption-Induced Segregation as a Method for the Target-Oriented Modification of the Surface of a Bimetallic Pd–Ag Catalyst
Stakheev, A. Yu.,Smirnova,Markov,Baeva,Bragina,Rassolov,Mashkovsky
, p. 610 - 617 (2018)
The effect of palladium segregation was studied which resulted from the effect of CO and O2 on the surface structure and catalytic characteristics of the Pd–Ag2/Al2O3 catalyst. The IR-spectroscopic study of adsorbed CO showed that Pd1 centers isolated from each other by silver atoms predominated on the surface of reduced Pd–Ag2/Al2O3, as evidenced by the almost complete absence of absorption bands typical for the multicentred CO adsorption. In the course of catalyst treatment with CO and O2, the intensity of absorption bands characteristic of the multicenter CO adsorption considerably increased due to the transformation of a portion of monatomic Pd1 centers into multiatomic Pdn ones as a result of the surface segregation of Pd. In this case, a substantial increase in the catalyst activity in the liquid-phase hydrogenation of diphenylacetylene was observed. It was established that, after treatment with CO, the catalyst selectivity for the formation of a target olefin (stilbene) remained almost constant, whereas the treatment with O2 led to a decrease in the selectivity because of more considerable surface modification.
Thorough examination of a Wittig-Horner reaction using reaction calorimetry (RC-1), LabMax, and ReactIR
Grabarnick, Michael,Zamir, Sharona
, p. 237 - 243 (2003)
The kinetics and thermodynamics of a Wittig-Horner reaction was investigated, together with side reactions such as the hydrolysis of benzyi phosphonate. It was found that the water content in the reaction mass has a crucial effect on the rates both of the unwanted hydrolysis of the phosphonate and of the main reaction. The reaction was found to be fourth-order. That means that the reaction is very fast at the start but tails off towards the end. On the basis of the kinetic and thermodynamic parameters, a simulation of the whole process was made, including the expected concentrations of the product under the required conditions (temperature, reactor characteristics, etc.). The experimental values of the concentrations were obtained from spectra collected via a rapid reaction mode in the ReactIR (a spectrum was collected every ～3 s). Exact agreement between experimental and theoretical values confirms the correctness of the mathematical model and enables right planning of the industrial process.
Cobalt-Catalyzed Redox-Neutral Sulfonylative Coupling from (Hetero)aryl Boronic Acids, Ammonium Salts and Potassium Metabisulfite
Zhang, Yingying,Zhu, Haibo,Fan, Qiangwen,Yang, Liu,Xie, Zongbo,Le, Zhang-Gao
, (2022/01/08)
An efficient cobalt-catalyzed redox-neutral sulfonylative coupling to afford (hetero)aryl alkyl sulfones from boronic acids, ammonium salts and potassium metabisulfite has been realized. Commercially available and air-stable CoCl2, in combination with phenanthroline ligand, is sufficient to achieve rapid and high-yielding conversion of the reactants into the corresponding sulfones. This practical transformation proceeds smoothly through C?N bond cleavage under redox-neutral catalytic conditions and shows broad functional-group tolerance. Other carbon based electrophiles, including diaryliodonium salts, heteroaryl halides, and carbonates were compatible. Further transformation of aryl alkyl sulfones then allows conversion into olefins, alkenyl sulfones and halogenated sulfones, respectively, in a one-pot process.
Heterometallic Mg?Ba Hydride Clusters in Hydrogenation Catalysis
Wiesinger, Michael,Knüpfer, Christian,Elsen, Holger,Mai, Jonathan,Langer, Jens,Harder, Sjoerd
, p. 4567 - 4577 (2021/09/09)
Reaction of a MgN“2/BaN”2 mixture (N“=N(SiMe3)2) with PhSiH3 gave three unique heterometallic Mg/Ba hydride clusters: Mg5Ba4H11N”7 ? (benzene)2 (1), Mg4Ba7H13N“9 ? (toluene)2 (2) and Mg7Ba12H26N”12 (3). Product formation is controlled by the Mg/Ba ratio and temperature. Crystal structures are described. While 3 is fully insoluble, clusters 1 and 2 retain their structures in aromatic solvents. DFT calculations and AIM analyses indicate highly ionic bonding with Mg?H and Ba?H bond paths. Also unusual H????H? bond paths are observed. Catalytic hydrogenation with MgN“2, BaN”2 and the mixture MgN“2/BaN”2 has been studied. Whereas MgN“2 is only active in imine hydrogenation, alkene and alkyne hydrogenation needs the presence of Ba. The catalytic activity of the MgN”2/BaN“2 mixture lies in general between that of its individual components and strong cooperative effects are not evident.
Highly selective semi-hydrogenation of alkynes with a Pd nanocatalyst modified with sulfide-based solid-phase ligands
Huang, Lingqi,Hu, Kecheng,Ye, Ganggang,Ye, Zhibin
, (2021/03/30)
Soluble small molecular/polymeric ligands are often used in Pd-catalyzed semi-hydrogenation of alkynes as an efficient strategy to improve the selectivity of targeted alkene products. The use of soluble ligands requires their thorough removal from the reaction products, which adds significant extra costs. In the paper, commercially available, inexpensive, metallic sulfide-based solid-phase ligands (SPL8-4 and SPL8-6) are demonstrated as simple yet high-performance insoluble ligands for a heterogeneous Pd nanocatalyst (Pd@CaCO3) toward the semi-hydrogenation of alkynes. Based on the reactions with a range of terminal and internal alkyne substrates, the use of the solid-phase ligands has been shown to markedly enhance the selectivity of the desired alkene products by efficiently suppressing over-hydrogenation and isomerization side reactions, even during the long extension of the reactions following full substrate conversion. A proper increase in the dosage or a reduction in the average size of the solid-phase ligands enhances such effects. With their insoluble nature, the solid-phase ligands have the distinct advantage in their simple, convenient recycling and reuse while without contaminating the products. A ten-cycle reusability test with the SPL8-4/Pd@CaCO3 catalyst system confirms its well-maintained activity and selectivity over repeated uses. A mechanistic study with x-ray photoelectron spectroscopy indicates that the solid-phase ligands have electronic interactions with Pd in the supported catalyst, contributing to inhibit the binding and further reaction of the alkene products. This is the first demonstration of solid-phase ligands for highly selective semi-hydrogenation of alkynes, which show strong promise for commercial applications.
