2143-88-6Relevant articles and documents
A palladium-loaded mesoporous polymer monolith as reusable heterogeneous catalyst for cross-coupling reactions
Kundu, Dhiman,Patra, Astam K.,Sakamoto, Junji,Uyama, Hiroshi
, p. 8 - 13 (2014)
A new palladium catalyst based on a mesoporous polymer monolith has been introduced. A polyacrylonitrile (PAN) monolith prepared by a phase separation technique was used as precursor material for chemical modification; the nitrile groups on the monolith surface were transformed into amidine groups and then bound to palladium dichloride via coordination. A series of Suzuki-Miyaura cross-coupling reactions were successfully demonstrated by using the monolith as catalyst. Moreover, the monolith was found to exhibit excellent stability for repeated use.
Guanidine/Pd(OAc)2-catalyzed room temperature Suzuki cross-coupling reaction in aqueous media under aerobic conditions
Li, Shenghai,Lin, Yingjie,Cao, Jungang,Zhang, Suobo
, p. 4067 - 4072 (2007)
(Chemical Equation Presented) A highly efficient Pd(OAc) 2/guanidine aqueous system for the room temperature Suzuki cross-coupling reaction has been developed. The new water-soluble and air-stable catalyst Pd(OAc)2·(1f)2 from Pd-(OAc)2 and 1,1,3,3-tetramethyl-2-n-butylguanidine (1f) was synthesized and characterized by X-ray crystallography. In the presence of Pd(OAc) 2·(1f)2, coupling of arylboronic acids with a wide range of aryl halides, including aryl iodides, aryl bromides, even activated aryl chlorides, was carried out smoothly in aqueous solvent to afford the cross-coupling products in good to excellent yields and high turnover numbers (TONs) (TONs up to 850 000 for the reaction of 1-iodo-4-nitrobenzene and phenylboronic acid). Furthermore, this mild protocol could tolerate a broad range of functional groups.
Highly active, durable and recyclable ordered mesoporous magnetic organometallic catalysts for promoting organic reactions in water
Zhang, Fang,Chen, Mingzhen,Wu, Xiaotao,Wang, Wei,Li, Hexing
, p. 484 - 491 (2014)
A new strategy of bonding organometallics to an MCM-41 thin layer coated onto Fe3O4 microspheres with strong magnetism, denoted as M-PPh2-MCM-41@SiO2@Fe3O4, where M = Pd(ii) and Rh(i), has been developed for the immobilization of homogeneous catalysts. In comparison with the traditional M-PPh2-MCM-41 catalysts with irregular shapes and the M-PPh2-SiO2@Fe 3O4 without an ordered mesoporous structure, the current catalysts exhibited much higher activities for various water-based Suzuki, Sonogashira and Miyaura-Michael organic reactions, due to the high dispersion of active sites and the uniform catalyst particles with short-ordered mesopores favoring reactant diffusion and adsorption. Their catalytic efficiencies are comparable with those of the homogeneous catalysts, and they could be easily recycled for reuse by simply applying an external magnet.
An efficient and reusable catalyst based on Pd/CeO2 for the room temperature aerobic Suzuki-Miyaura reaction in water/ethanol
Amoroso, Francesco,Colussi, Sara,Del Zotto, Alessandro,Llorca, Jordi,Trovarelli, Alessandro
, p. 197 - 204 (2010)
The Pd/CeO2 system behaves as an efficient precatalyst for the Suzuki-Miyaura cross-coupling under mild conditions (298 K, in air) in ethanol/water. A broad range of aryl bromides, including those deactivated, and arylboronic acids underwent Suzuki-Miyaura coupling with quantitative GC yields of asymmetric biaryls. Isolated yields and purity of the coupling products were good to excellent. A careful investigation through a series of suitable tests unequivocally showed that the C-C cross-coupling is accomplished via homogeneous mechanism by leached palladium(0). Noticeably, the Pd/CeO2 system can be recycled at least ten times without loss of activity.
Stille-type aryl-aryl cross-coupling catalysis using triarylphosphine ligands with electron-rich Fe(ii)-alkynyl substituents
Grelaud, Guillaume,Tohme, Ayham,Argouarch, Gilles,Roisnel, Thierry,Paul, Frederic
, p. 2740 - 2742 (2011)
The synthesis of four new phosphane ligands featuring electron-rich Fe(ii) "(η2-dppe)(η5-C5Me 5)FeCC-" substituents in para and meta position(s) on the aryl rings (1-4) is reported along with those of the corresponding PdCl 2(PAr3)2 precatalysts (7-10). These precatalysts have then been tested in a Stille-type aryl-aryl cross coupling reaction. It is shown that these new ligands survive the reaction conditions and perform at least as well as the classic triphenylphosphine ligand for this transformation.
Studies on the catalytic ability of palladium wire, foil and sponge in the Suzuki-Miyaura cross-coupling
Amoroso, Francesco,Cersosimo, Ulma,Del Zotto, Alessandro
, p. 256 - 262 (2011)
Different forms of metallic palladium (wire, foil and sponge) have been tested as potential catalysts in the Suzuki-Miyaura cross-coupling. All samples showed to be catalytically active for both electron-poor and electron-rich aryl bromides combined with a variety of arylboronic acids. Palladium wire has been recycled six times without decrease of activity. A series of poisoning experiments demonstrated that the true catalyst is a soluble form of palladium arising from a leaching process. Interestingly, metal leaching from palladium foil has been clearly evidenced by SEM.
Facile Synthesis of Magnetic Hierarchical Core–Shell Structured Fe3O4@PDA-Pd@MOF Nanocomposites: Highly Integrated Multifunctional Catalysts
Ma, Rong,Yang, Pengbo,Ma, Yao,Bian, Fengling
, p. 1446 - 1454 (2018)
A magnetic hierarchical core–shell structured Fe3O4@PDA-Pd@[Cu3(btc)2] nanocomposite has been fabricated via a facile layer-by-layer assembly method. It contains a core of polydopamine (PDA)-modified magnetic Fe3O4 nanoparticles (NPs), a transition layer of Pd NPs, and a porous outer shell of copper-based metal–organic framework (MOF) with controllable thickness. This novel nanocomposite was characterized by TEM, FTIR, XRD, XPS, N2 adsorption–desorption isotherms, and VSM. The prepared Fe3O4@PDA-Pd@[Cu3(btc)2] (n=5) nanocomposite shows ultrahigh catalytic activity for the 4-nitrophenol reduction and Suzuki–Miyaura coupling reactions of aryl halides (Br, Cl) with arylboronic acids. Moreover, the nanocomposite also can be easily separated by an external magnet and reused at least 8 runs with excellent yields for both the reactions. The catalyst has outstanding catalytic performance, mainly because the integration of [Cu3(btc)2] with Fe3O4@PDA-Pd that combines the advantages of each component could exhibit a synergistic effect in the catalytic system.
Enhancing activity of Suzuki reactions in water by using guanidinium ionic liquid stabilized palladium micelle catalyst
Lin, Li,Li, Yanchun,Zhang, Suobo,Li, Shenghai
, p. 1779 - 1783 (2011)
A facile surfactant-based hexaalkylguanidinium ionic liquid (GIL)-mediated Suzuki coupling procedure has been developed using ligand-free Pd catalysts. The procedure involving the use of nanometric palladium micelles, is operationally simple and remarkably efficient for the coupling of aryl bromides or aryl chlorides with boronic acids in water. Furthermore, the GIL/H2O catalytic system was more stable than the tetrabutylammonium bromide/H 2O catalytic system under basic conditions, enabling the recycling of the nano-Pd micelle catalysts. Georg Thieme Verlag Stuttgart · New York.
C–Hortho?Pd interactions in palladium complexes derived from tetrasulfur-difluorinated ligands. Experimental, computational and catalytic studies
González-Montiel, Simplicio,Sandoval-Chávez, César Ignacio,Mu?oz-Granados, Oscar,Martínez-Otero, Diego,Vásquez-Pérez, J. Manuel,Cruz-Borbolla, Julián,Velázquez-Jiménez, René,López, Jorge A.
, (2019)
The symmetric ligands [Ar-S-CH2-Ph-S-(CH2)-]2, L1 (Ar = o-FPh) and L2 (Ar = p-FPh), and their PdII complexes (1 and 2) were synthesized and structurally characterized. Molecular structures of complexes 1 and 2 display the L1 and L2 ligands coordinating palladium in a κ2-SS bidentate fashion. The metal center exhibits a square planar geometry involving the two sulfur atoms and two chloride atoms which are oriented in cis disposition. Interestingly, the two ortho-hydrogen atoms from the phenyl rings in both complexes are engaged in Pd?Hortho interactions with distances from 2.976 to 3.280 ?. These distances can suffer an increase or decrease in their longitude due to the presence of intramolecular C–H?π interactions. Additionally, the presence of Pd?H interactions in palladium complexes (1 and 2) were identified by an NCI analysis. The complexes 1, 2 and a similar complex 3 that also displays Pd?Hortho interactions have been evaluated in the Suzuki-Miyaura cross-coupling reactions.
Synthesis and catalytic activity of cationic dinuclear palladium (II) complexes supported by thioether ligands containing two di-(2-picolyl) amine arms
Andrade-López, Noemi,González-Montiel, Simplicio,Martínez-Otero, Diego,Salazar-Pereda, Verónica,Sandoval-Chávez, César Ignacio,Velázquez-Jiménez, René
, (2020)
The design, synthesis and characterization of a series of dithioether ligands featuring two di-(2-picolyl)amine arms (2a–2d) and their corresponding cationic dinuclear palladium (II) complexes (3a–d) are reported. Crystal structures of ligand 2b and complexes 3b and 3d were determined by X-ray diffraction studies. The molecular structures of 3b and 3d display each of the two di-(2-picolyl)amine fragments coordinated to one palladium(II) atom in a (κ3-N,N,N) tridentate fashion and with the cationic metal centers displaying square-planar geometries. Weak interactions between the metal centers and the thioether fragments are observed. All bimetallic complexes 3a–d were tested as catalytic precursors in the Suzuki couplings of different o- or p-substituted iodo- or bromoaryls with boronic acids. The overall catalytic results indicate that complex 3b is the best precursor of the series demonstrating even more efficient performance compared to commercial palladium sources such as Pd(OAc)2 and the Nájera Catalysts.
