1694-20-8Relevant articles and documents
Cis/trans conversion of potassium derivatives of 2- and 4-nitrostilbenes
Todres, Zori V.
, p. 349 - 354 (1992)
Potassium derivatives of 2- and 4-nitrostilbenes exist in non-dissociating solvents as coordination complexes with localization of the metal at the nitro group.Stilbene components of the complexes undergo cis/trans conversion, the extent of which does not
A new recyclable Pd catalyst supported on vertically aligned carbon nanotubes for microwaves-assisted Heck reactions
Janowska, Izabela,Chizari, Kambiz,Olivier, Jean-Hubert,Ziessel, Raymond,Ledoux, Marc Jacques,Pham-Huu, Cuong
, p. 663 - 670 (2011)
Palladium supported on vertically aligned multi-walled carbon nanotubes (Pd/VA-CNTs) is used as catalyst for the C-C coupling reactions of p-iodonitrobenzene with styrene and ethyl acrylate under microwaves irradiation. Pd/VA-CNTs catalyst exhibits higher
Mild and rational synthesis of palladium complexes comprising C(4)-bound N-heterocyclic carbenes
Kluser, Evelyne,Neels, Antonia,Albrecht, Martin
, p. 4495 - 4497 (2006)
Oxidative addition of pyridyl-functionalised 4-iodoimidazolium salts to palladium(0) gives catalytically active complexes in which the N-heterocyclic carbene is bound to the palladium(ii) centre in a non-classical bonding mode via C(4). The Royal Society of Chemistry 2006.
Oxazoline Chemistry. Part 11: Syntheses of natural and synthetic isoflavones, stilbenes and related species via C-C bond formation promoted by a Pd-oxazoline complex
Eisnor, Charles R.,Gossage, Robert A.,Yadav, Paras N.
, p. 3395 - 3401 (2006)
The complex trans-[PdCl2(2-ethyl-2-oxazoline- κ1N)2] (1) is shown to be an active and oxidatively robust catalyst for C-C bond forming reactions (Heck, Sonogashira, Ullmann, Miyaura-Suzuki, etc.). These reactions can be carried out in air without rigorous solvent/substrate purification and in the absence of additional free ligand. The general methodology described above has been applied to the high yield and regio-selective formation, via Miyaura-Suzuki coupling, of natural and synthetic isoflavones (i.e., isoflavone, 2′-methylisoflavone [7b], 3′-methylisoflavone [7c] and 3′,4′-benzoisoflavone: [7d]). Compounds 7c and 7d are previously unknown. In addition, the synthesis of (E)-tris-O-methylresveratrol and (E)-3,5-dimethoxystilbene is also described; the former is a recognized anti-cancer agent while the latter is a biologically active extract from the bark of the conifer species Pinus armandii. Both of these latter products are produced as a result of a Heck coupling reaction promoted by 1.
Application of an air stable Pd oxazoline complex for Heck, Suzuki, Sonogashira and related C-C bond-forming reactions
Gossage, Robert A.,Jenkins, Hilary A.,Yadav, Paras N.
, p. 7689 - 7691 (2004)
The novel complex trans-[PdCl2(η1-N-2-ethyl-2- oxazoline)2] is shown to be an active and oxidatively robust catalyst for C-C bond-forming reactions (Heck, Sonogashira, Ullman, Suzuki), which can be carried out in air witho
Enhanced Heck reaction on flower-like Co(Mg or Ni)Al layered double hydroxide supported ultrafine PdCo alloy nanocluster catalysts: The promotional effect of Co
Li, Jin,Song, Ying,Wang, Yajuan,Zhang, Hui
, p. 17741 - 17751 (2019)
A series of PdCo alloy nanocluster (NC) catalysts x-PdCor/Co(Mg or Ni)Al-LDH (x: Pd loading, r: Co/Pd molar ratio) were synthesized by immobilizing ultrafine PdCor-PVP NCs on flower-like layered double hydroxide (LDH) supports. The s
Palladium Loaded Dendronized Polymer as Efficient Polymeric Sustainable Catalyst for Heck Coupling Reaction
Hiba, K.,Krishna, G. Anjali,Prathapan, S.,Sreekumar, K.
, (2021/08/18)
The palladium incorporated amine-functionalized dendronized polymer was synthesized by the addition of palladium acetate to dendronized polymer in methanol at room temperature. Palladium species are immobilized onto the dendritic structure by their coordination with amino functional groups. The newly developed dendritic system showed high palladium content in the low generation level itself, which was found to be 4.19?mmol/g. This was fairly higher than, the other palladium-based catalysts. Energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, UV–Visible spectroscopy, and X-ray photoelectron spectroscopy were used to confirm the successful synthesis of the new catalyst. It was used as a homogeneous palladium catalyst for Heck coupling reaction between olefins and differently substituted aryl halides and the products were isolated in high yield. The products isolated were in trans configuration, which indicated the selectivity of the newly developed catalytic system. Also, this catalyst system was reused up to nine times without a significant decrease in its catalytic activity. The easy accessibility of catalytic sites, stability, resistance to metal leaching, high catalytic activity and remarkable stereoselectivity with a low amount of catalyst are all due to the dendritic support. The docking study was carried out for all the stilbene derivatives obtained by the Heck coupling reaction against DprE1 protein to study its potential antitubercular activity. All the compounds displayed superior docking score values over the range ??6.5 to ??8.2?kcal/mol, compared to the standard drug isoniazid with docking score of ??6.1?kcal/mol against DprE1. Graphic Abstract: [Figure not available: see fulltext.]
Immobilized Pd on a NHC-functionalized metal-organic FrameworkMIL-101(Cr): An efficient heterogeneous catalyst in the heck and copper-free Sonogashira coupling reactions
Niknam, Esmaeil,Panahi, Farhad,Khalafi-Nezhad, Ali
supporting information, (2021/01/12)
A heterogeneous palladium catalyst system based on immobilization of palladium moieties on a N-heterocyclic carbene (NHC) modified metal organic framework (MOF) was developed for the Heck and copper-free Sonogashira coupling reactions. In order to prepare this catalyst system, first, MIL-101(Cr) was functionalized with NHC moieties through a post synthetic modification (PSM) approach, and then Pd metal was stabilized on the prepered MIL-101(Cr)-NHC substrate. This material was characterized using various microscopic and spectroscopic techniques and then was used as an efficient heterogeneous Pd catalyst system in the Heck and copper-free Sonogashira reactions. Results of the heterogeneity tests showed that the Pd-NHC-MIL-101(Cr) catalyst can efficiently catalyzed these coupling reactions heterogeneously and no remarkable changes observed in the morphology and structure of MIL-101(Cr) template during the reaction progress. Also, existence of palladium nanoparticles immobilized on the MOF structure affirmed by the TEM and XPS analysis confirmed the oxidation state of Pd. A variety of alkene and alkyne derivatives were synthesized in good to excellent yields using this heterogeneous Pd catalyst system under normal conditions. More importantly Pd-NHC-MIL-101(Cr) catalyst was simply recovered from the reaction medium without remarkable decreasing in its catalytic activities after five times of reusability. The ICP analysis showed the very low Pd and Cr metals leaching, representing high stability and applicability of this catalyst in Pd coupling reactions.
Palladium Nanoparticles Anchored on Magnesium Organosilicate: An Effective and Selective Catalyst for the Heck Reaction
Dos Santos, Beatriz F.,Da Silva, Beatriz A. L.,De Oliveira, Aline R.,Sarragiotto, Maria H.,Rinaldi, Andrelson W.,Domingues, Nelson Luís C.
supporting information, p. 1301 - 1306 (2020/11/04)
A new and effective palladium catalyst supported on a magnesium organosilicate for application in the Heck reaction is presented. A group of compounds comprising 22 examples were synthesized in moderate to high yields (up to 99%) within a short time. The palladium supported on magnesium organosilicate catalyst was characterized as an amorphous solid by SEM, containing around 33% of palladium inside the solid, and even with this low quantity of palladium, the catalyst was very efficient in the Heck reaction. Besides, based on the Scherrer equation, the crystallite size of the synthesized palladium nanoparticles was ultrasmall (around 1.3 nm). This strategy is a simple and efficient route for the formation of C-C bonds via the Heck cross-coupling reaction.