17088-28-7Relevant academic research and scientific papers
A magnetic palladium nickel carbon nanocomposite as a heterogeneous catalyst for the synthesis of distyrylbenzene and biphenyl derivatives
Shafie, Habiballah,Niknam, Khodabakhsh
supporting information, p. 11697 - 11704 (2021/07/12)
A magnetic palladium nickel carbon (Fe3O4@Pd@Ni/C) nanocomposite has been synthesized using a simple one-pot procedure via a hydrothermal approach. Ferric nitrate, palladium acetate, and nickel nitrate were dissolved in water together with glucose, and the mixture was heated in an autoclave. The Fe3O4@Pd@Ni/C nanocomposite was characterized via XRD, TEM, FE-SEM, VSM, EDS, and XPS studies. The catalytic abilities of the Fe3O4@Pd@Ni/C nanocomposite were investigated for the synthesis of distyrylbenzene and 9,10-distyrylanthracene derivatives. This method shows obvious advantages, such as the recyclability of the catalyst, simple experimental operation, and the obtaining of good to excellent yields.
The Cooperative Effect of Both Molecular and Supramolecular Chirality on Cell Adhesion
Liu, Jinying,Yuan, Feng,Ma, Xiaoyu,Auphedeous, Dang-i Y.,Zhao, Changli,Liu, Chuntai,Shen, Changyu,Feng, Chuanliang
, p. 6475 - 6479 (2018/05/08)
Although helical nanofibrous structures have great influence on cell adhesion, the role played by chiral molecules in these structures on cells behavior has usually been ignored. The chirality of helical nanofibers is inverted by the odd–even effect of methylene units from homochiral l-phenylalanine derivative during assembly. An increase in cell adhesion on left-handed nanofibers and weak influence of cell behaviors on right-handed nanofibers are observed, even though both were derived from l-phenylalanine derivatives. Weak and negative influences on cell behavior was also observed for left- and right-handed nanofibers derived from d-phenylalanine, respectively. The effect on cell adhesion of single chiral molecules and helical nanofibers may be mutually offset.
Ligand-accelerated non-directed C-H functionalization of arenes
Wang, Peng,Verma, Pritha,Xia, Guoqin,Shi, Jun,Qiao, Jennifer X.,Tao, Shiwei,Cheng, Peter T. W.,Poss, Michael A.,Farmer, Marcus E.,Yeung, Kap-Sun,Yu, Jin-Quan
, p. 489 - 493 (2017/11/28)
The directed activation of carbon-hydrogen bonds (C-H) is important in the development of synthetically useful reactions, owing to the proximity-induced reactivity and selectivity that is enabled by coordinating functional groups. Palladium-catalysed non-directed C-H activation could potentially enable further useful reactions, because it can reach more distant sites and be applied to substrates that do not contain appropriate directing groups; however, its development has faced substantial challenges associated with the lack of sufficiently active palladium catalysts. Currently used palladium catalysts are reactive only with electron-rich arenes, unless an excess of arene is used, which limits synthetic applications. Here we report a 2-pyridone ligand that binds to palladium and accelerates non-directed C-H functionalization with arene as the limiting reagent. This protocol is compatible with a broad range of aromatic substrates and we demonstrate direct functionalization of advanced synthetic intermediates, drug molecules and natural products that cannot be used in excessive quantities. We also developed C-H olefination and carboxylation protocols, demonstrating the applicability of our methodology to other transformations. The site selectivity in these transformations is governed by a combination of steric and electronic effects, with the pyridone ligand enhancing the influence of sterics on the selectivity, thus providing complementary selectivity to directed C-H functionalization.
Ruthenium(II)-salen complexes-catalyzed olefination of aldehydes with ethyl diazoacetate
Sun, Wei,Yu, Bingsheng,Kühn, Fritz E.
, p. 1993 - 1996 (2007/10/03)
Several salen-ruthenium(II) complexes, which are derived from commercial ligands or simply ethylenediamine, can be successfully applied as catalysts for the olefination of a broad variety of aldehydes. Depending on the electron richness of the applied aldehydes, good to very good olefin yields and high E:Z selectivities are reached at 60 or 80°C reaction temperature with ethyl diazo acetate being the reaction partner. The reaction rate depends on the electron donor capabilities of the aldehydes. Electron poor aldehydes undergo faster reactions than electron rich aldehydes, but both electron rich and bulky aldehydes can be transformed to corresponding olefins in very good yields and high E-selectivity.
One-pot selective oxidation/olefination of primary alcohols using TEMPO-BAIB system and stabilized phosphorus ylides
Vatèle, Jean-Michel
, p. 715 - 718 (2007/10/03)
A one-pot process for the synthesis of α,β-unsaturated esters from a variety of alcohols, obtained in good yields and diastereoselectivities, is described. The use of BAIB/TEMPO system at the oxidizing step authorizes the chemoselective homologation of primary alcohols in the presence of secondary ones.
Preparation of a Nafion-Teflon bimembrane-supported palladium catalyst and its use in the Heck reaction
Li, Yangzhou,Li, Zhiming,Li, Feng,Wang, Quanrui,Tao, Fenggang
, p. 6159 - 6162 (2007/10/03)
A novel palladium catalyst supported on the Nafion membrane, reinforced with poly(tetrafluoroethylene) fiber, has been prepared. The catalyst exhibits high activity and stability in the Heck arylation reactions of aryl iodides with olefins and Sonogashira couplings with phenylacetylene, and can be readily recovered and reused twenty times without significant loss of activity.
Stereospecific preparation of ethyl (E) and (Z)-3-aryl-3-phenylpropenoates by Heck reaction
Moreno-Manas, Marcial,Perez, Montserrat,Pleixats, Roser
, p. 7449 - 7452 (2007/10/03)
Ethyl cinnamate reacts with several para-substituted aryl iodides under Jeffery-Larock conditions (Pd(OAc)2, NaHCO3, n-Bu4NBr, DMF, Δ) to give ethyl (E)-3-aryl-3-phenylpropenoates as major compounds. The reaction of para-substituted ethyl cinnamates with iodobenzene under analogous conditions affords the corresponding Z isomers. The initially stereodefined alkene formed under Heck conditions undergoes a slow isomerization.
REACTIONS DE WITTIG-HORNER ET DE TRANSESTERIFICATION EN UNE OPERATION PAR ACTIVATION ANIONIQUE DE LIAISONS C-H ET O-H EN MILIEU HETEROGENE CARBONATE DE POTASSIUM/ALCOOL
Mouloungui, Z.,Elmestour, R.,Delmas, M.,Gaset, A.
, p. 1219 - 1232 (2007/10/02)
The Wittig-Horner reaction carried out in various alcohols is accompanied by transesterification of the alkyl radical of the α,β-ethylenic ester formed.The occurrence of these two reactions in the same reaction medium is affected by the behavior of: i) the alcohol (solvent and reagent), ii) potassium carbonate (reagent and catalyst).The propensity for the two reactions to occur was found to depend on the polarity of the alcohol.Protic alcohols speeded both the Wittig-Horner and the subsequent transesterification reaction.Both reactions were quantitative despite the use of non-stoichiometric amounts of potassium carbonate.Regeneration in situ of the solid base observed in aprotic medium was markedly enhanced under these reaction conditions.The mechanism proposed for these two reactions incorporates this regeneration process.
