1149-56-0Relevant academic research and scientific papers
Palladium catalyst systems for cross-coupling reactions of aryl chlorides and olefins
Zapf, Alexander,Beller, Matthias
, p. 2908 - 2915 (2001)
A detailed investigation into the influence of phosphines, additives, bases and solvents on the Heck coupling reaction of 4-trifluoromethyl-1-chlorobenzene (2) is presented. It is shown that a number of catalyst systems exist for efficient cross coupling of electron-deficient aryl chlorides with various olefins. Basicity and steric demand of the ligand are two factors which determine the success of the reaction. In addition the phosphine/palladium ratio, the correct type and amount of additive, and finally the use of an appropriate base and solvent are also important. The optimised reaction conditions are applied for the arylation of styrene, 2-ethylhexyl acrylate and N,N-dimethyl acrylic amide with various aryl chlorides.
Preparation of palladium colloids in block copoloymer micelles and their use for the catalysis of the heck reaction
Klingelh?fer,Heitz,Greiner,Oestreich,F?rster,Antonietti
, p. 10116 - 10120 (1997)
Colloidal dispersions of nanometer sized palladium colloids with very high stability were prepared in block copolymer micelles of polystyrene-b-poly-4-vinylpyridine and analyzed by electron microscopy and X-ray analysis. The resulting polymer/metal hybrids can easily be dissolved and handled in standard organic solvents such as toluene, tetrahydrofuran, and cyclohexane. They were successfully used for the Pd-catalyzed carbon-carbon coupling of aryl halides with alkenes (Heck reaction). Such block copolymer stabilized palladium colloids exhibit about the same activity as low molecular weight Pd complexes classically used for the Heck reaction, but show a much higher stability: in most reactions, the hybrids remain catalytically active even after 50000 turn-over cycles. Reaction rates were significantly controlled by the reactivity of the educts, but also respond to micelle architecture and dispersity of the palladium. Other advantages of the block copolymer stabilizer are that they are more simple and readily accessible than the phosphor-containing chelate, and that they dissolve even in 'simple' solvents such as toluene (instead of amidic solvents).
Alkenyldimethyl(2-thienyl)silanes, excellent coupling partner for the palladium-catalyzed cross-coupling reaction
Hosoi, Kazushi,Nozaki, Kyoko,Hiyama, Tamejiro
, p. 138 - 139 (2002)
Introduction of a 2-thienyl group to the silicon atom of alkenylsilanes promoted the cross-coupling reaction with aryl halides mediated by tetrabutylammonium fluoride and a palladium catalyst. The reaction proceeded under extremely mild conditions to affo
Niobium(v)-catalyzed defluorinative triallylation of α,α,α-trifluorotoluene derivatives by triple C-F bond activation
Saito, Kodai,Umi, Taishi,Yamada, Takayuki,Suga, Takuya,Akiyama, Takahiko
, p. 1767 - 1770 (2017)
The catalytic defluorinative triallylation of α,α,α-trifluorotoluene derivatives via C-F bond activation has been achieved by the use of the NbCl5 catalyst and allyltrimethylsilane as a nucleophile. Several control experiments have suggested the importance of the conjugation between the fluorine atoms and the carbocation center in this reaction.
Reusable and sustainable nanostructured skeleton catalyst: Heck reaction with nanoporous metallic glass Pd (PdNPore) as a support, stabilizer and ligand-free catalyst
Kaneko, Tetsuro,Tanaka, Shinya,Asao, Naoki,Yamamoto, Yoshinori,Chen, Mingwei,Zhang, Wei,Inoue, Akihisa
, p. 2927 - 2932 (2011)
Nanoporous metallic glass palladium (PdNPore), which was fabricated by de-alloying of a glassy metallic alloy Pd30Ni50P 20, exhibited a remarkable catalytic activity for the Heck reaction of versatile aryl iodides and aryl bromides. Moreover, the PdNPore can be reused several times without a significant loss of catalytic activity, and the PdNPore has ahigher resistance to leaching than palladium black and palladium on carbon. Copyright
Palladium nanoparticles generated from allylpalladium chloride in situ: A simple and highly efficient catalytic system for Mizoroki-Heck reactions
Wang, Wei,Yang, Qin,Zhou, Rong,Fu, Hai-Yan,Li, Rui-Xiang,Chen, Hua,Li, Xian-Jun
, p. 1 - 5 (2012)
The Mizoroki-Heck reactions of aryl halides catalyzed by palladium nanoparticles generated in situ from a simple allyl palladium precursor were investigated in argon. The high turnover numbers of 9,300,000 have been obtained with 4-bromobenzonitrile as substrate and 3500 with 4-nitrochlorobenzene. When the reaction was performed in air, a low yield was given, but it could be improved obviously by addition of PEG-400. The main reason was that inactive Pd(II) species could be rapidly reduced to the active Pd(0) by PEG. In other word, the existence of air and PEG led to a synergistic effect which the oxidation by air prevents the aggregation of Pd NPs and the reduction by PEG maintains the high activity of Pd(0) species.
Pd- and Ni-Pyridyl Complexes Deposited as Films for Suzuki-Miyaura and Mizoroki-Heck Cross Coupling Reactions
Zhao, Xiuhua,Zhang, Jie,Zhao, Yayun,Li, Xing
, p. 2010 - 2019 (2015)
A pyridyl fluorene ligand, 2,7-bis(4-pyridyl)-9,9-diethylfluorene (1), has been synthesized by a simple route. The ability of the two linearly terminal pyridyl nitrogen atoms of 1 to coordinate with the Pd(II) or Ni(II) ions has enabled the use of 1 as a linking ligand in the preparation of (PdCl2/1) n, (Ni(NO3)2/1) n films, PdCl2/1 and Ni(NO3)2/1 complex. The resulting films and complexes were characterized by UV-vis spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectrometer. The application of films and complexes as catalysts for Suzuki-Miyaura and Mizoroki-Heck reactions was carried out. (PdCl2/1) n films show high catalytic activity in the reactions with the Pd loading of ppm. (Ni(NO3)2/1) n multilayers as the active catalytic moieties for these reactions were investigated with very low Ni(II)-loading. Graphical Abstract: The (Pd or Ni/1) n multilayer films were used as high active catalysts for the C-C formation with extremely low M(II)-loading in ppm level.[Figure not available: see fulltext.]
Mono- and dinuclear N-heterocyclic carbene palladium complexes with diazine ligands and their catalytic activities toward the Mizoroki–Heck reaction
Yang, Jin
, p. 3749 - 3758 (2017)
Mono- and dinuclear N-heterocyclic carbene palladium complexes with diazine ligands were synthesized and characterized through adjusting the stoichiometric ratio of the reactants. The catalytic properties of all complexes were further studied in the Mizor
D -glucosamine as a green ligand for palladium-catalyzed cross-coupling of aryl and heteroaryl halides
Jha, Abadh Kishor,Shahni, Rahul Kumar,Jain, Nidhi
, p. 259 - 264 (2015)
Naturally occurring d-glucosamine works as an efficient green alternative to phosphines in palladium-catalyzed Heck coupling of aryl and heteroaryl halides. An array of trans-stilbene derivatives, aryl naphthyl alkenes, heteroaryl olefins, and β-aryl-substituted acrylates has been synthesized in short reaction times in moderate to high yields.
Selenium-ligated palladium(II) complexes as highly active catalysts for carbon-carbon coupling reactions: The Heck reaction
Yao, Qingwei,Kinney, Elizabeth P.,Zheng, Chong
, p. 2997 - 2999 (2004)
(Equation Presented) Three selenium-ligated Pd(II) complexes were readily synthesized and shown to be extremely active catalysts for the Heck reaction of various aryl bromides, including deactivated and heterocyclic ones. The catalytic activity of the selenide-based Pd(II) complexes not only rivals but vastly outperforms that of the corresponding phosphorus and sulfur analogues. Practical advantages of the selenium-based catalysts include their straightforward synthesis and high activity in the absence of any additives as well as the enhanced stability of the selenide ligands toward air oxidation.
