588-59-0Relevant articles and documents
Synthesis, structure and hydrogenation catalytic activity of 3,η2-ampy)(μ,η1:η2-PhC=CHPh)(CO)6(PPh3)2> (Hampy = 2-amino-6-methylpyridine)
Cabeza, Javier A.,Llamazares, Angela,Riera, Victor,Briard, Pierrette,Ouahab, Lahcene
, p. 205 - 212 (1994)
The compound 3,η2-ampy)(μ,η1:η2-PhC=CHPh)(CO)6(PPh3)2> (1) (ampy = 2-amino-6-methylpyridinate) has been prepared by reaction of 3,η2-ampy)(μ,η1:η2-PhC=CHPh)(CO)7(PPh3)> with triphenylphosphine at room temperature.However, the reaction of 3,η2-ampy)(CO)7(PPh3)2> with diphenylacetylene requires a higher temperature (110 deg C) and does not give complex 1 but the phenyl derivative 3,η2-ampy)(μ,η1:η2-PhC=CHPh)(μ-PPh2)(Ph)(CO)5(PPh3)> (2).The thermolysis of complex 1 (110 deg C) also gives complex 2 quantitatively.Both 1 and 2 have been characterized by X-ray diffraction methods.Complex 1 is a catalyst precursor for the homogeneous hydrogenation of diphenylacetylene to a mixture of cis- and trans-stilbene under mild conditions (80 deg C, 1 atm. of H2), although progressive deactivation of the catalytic species is observed.The dihydride 3,η2-ampy)(μ,η1:η2-PhC=CHPh)(CO)5(PPh3)2> (3), which has been characterized spectroscopically, is an intermediate in the catalytic hydrogenation reaction. Key words: Ruthenium; X-ray diffraction; Hydrogenation; Homogenous catalysis; Clusters; Phosphine
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
Investigation of the Wittig reaction with electrogenerated bases: Influence of experimental conditions on the yield and stereochemistry
Bettencourt, Ana Paula,Freitas, Ana Maria,Montenegro, M. Irene
, p. 4397 - 4400 (1999)
The influence of experimental parameters on the yields and stereochemistry of the Wittig reaction was studied using the synthesis of stilbene initiated by different electrogenerated bases as a model reaction. Electrolyses were carried out in batch cells under different conditions, including constant potential or constant current with different electrode materials and using solvents of different polarity. It is shown that proper selection of experimental conditions in Wittig reactions allows a choice of stereoselectivity in the reactions and the optimization of yields.
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.
Synthesis and catalytic application of palladium nanoparticles supported on kaolinite-based nanohybrid materials
Ngnie, Gaelle,Dedzo, Gustave K.,Detellier, Christian
, p. 9065 - 9072 (2016)
Palladium nanoparticles (PdNPs) were deposited on the surface of the modified clay mineral, kaolinite. To improve compatibility, abundance and control of the size of the nanoparticles, kaolinite was modified by the grafting of an amino alcohol (triethanol
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.
From 4-nitrotoluene and 4,4′-dinitrobibenzyl to: E -4,4′-dinitrostilbene: An electrochemical approach
Gallardo, Iluminada,Gómez, Ana Belén,Guirado, Gonzalo,Lari?o, Adrián,Moreno, Miquel,Ortigosa, Manuel,Soler, Sergio
, p. 7005 - 7015 (2018)
The dianions formed by the electroreduction of Z-O2NC6H4CHCHC6H4NO2, E-O2NC6H4CHCHC6H4NO2, O2NC6H4CH2-CH2C6H4NO2 or O2NC6H4CMeH-CMeHC6H4NO2, as well as the anion radical arising from 4-nitrotoluene, are stable, in the time scale of cyclic voltammetry (DMF + 0.10 M NBu4BF4). However, in the electrolysis time scale (from minutes to hours), only the dianion O2NC6H4CMeH-CMeHC6H4NO22- remains stable, since the reduced species, Z-O2NC6H4CHCHC6H4NO22-, O2NC6H4CH2-CH2C6H4NO22- or O2NC6H4Me-, evolve to form the E-O2NC6H4CHCHC6H4NO22- dianion. This intermediate is recovered as the neutral species E-O2NC6H4CHCHC6H4NO2 with concomitant water reduction after the work-up with water, as demonstrated by combined electrolysis, cyclic voltammetry experiments, UV-spectroelectrochochemistry and theoretical calculations. Bulk electrolysis under optimized conditions (ACN + 0.10 M NBu4BF4) provides 40% and 67% isolated yields of E-4,4′-dinitrostilbene from 4-nitrotoluene and 4,4′-dinitrobibenzyl, respectively.
Addition of Diazoalkanes to Enynes Promoted by a Ruthenium Catalyst: Simple Synthesis of Alkenyl Bicyclo[3.1.0]hexane Derivatives
Monnier, Florian,Castillo, Dante,Derien, Sylvie,Toupet, Loic,Dixneuf, Pierre H.
, p. 5474 - 5477 (2003)
[C*pRuCl(cod)] (C*p=C5Me 5, cod=cyclooctadiene) promotes the reaction of 1,6-enynes with an excess of diazoalkane in dioxane in one step to afford selectively 1-alkenyl bicyclo[3.1.0]hexane derivatives (see scheme, X=O, NTs; Y=CO2Et; R1=H, Me; R2=H; Ts=p-toluenesulfonyl). This novel reaction involves the stereoselective formation of three C-C bonds and a cyclopropanation step.
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
