1149-56-0Relevant articles and documents
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.
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
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.
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
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.
An efficient Pd-NHC catalyst system in situ generated from Na2PdCl4 and PEG-functionalized imidazolium salts for Mizoroki-Heck reactions in water
Sun, Nan,Chen, Meng,Jin, Liqun,Zhao, Wei,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan
, p. 1735 - 1744 (2017)
Three PEG-functionalized imidazolium salts L1-L3 were designed and prepared from commercially available materials via a simple method. Their corresponding water soluble Pd-NHC catalysts, in situ generated from the imidazolium salts L1-L3 and Na2PdCl4 in water, showed impressive catalytic activity for aqueous Mizoroki-Heck reactions. The kinetic study revealed that the Pd catalyst derived from the imidazolium salt L1, bearing a pyridine-2-methyl substituent at the N3 atom of the imidazole ring, showed the best catalytic activity. Under the optimal conditions, a wide range of substituted alkenes were achieved in good to excellent yields from various aryl bromides and alkenes with the catalyst TON of up to 10,000.
Structural Effect of Pincer Pd(II)–ONO Complexes Modified with Acylthiourea on Sizes of the In Situ Generated Pd Nanoparticles During Heck Coupling Reaction
Jerome,Babu, S. Ganesh,Karvembu
, p. 1633 - 1645 (2021)
Abstract: The Pd nanoparticles generated in situ from Pd–pincer complexes catalyzed Heck coupling reaction. For this purpose, new Pd(II)–ONO pincer complexes (1–4) containing acylthiourea ancillary ligand were obtained by treating [Pd(ONO)(CH3CN)] with the respective N-substituted carbamothioyl benzamide ligand (L1–L4). Formation of these complexes was confirmed by UV–Visible, FT-IR, NMR and mass spectroscopic techniques. The sizes of in situ formed Pd nanoparticles were greatly affected by the substituent in ancillary ligand, which in turn influenced their catalytic activity towards Heck coupling reaction. The in situ formed Pd nanoparticles during Heck reaction were removed from the reaction medium and analyzed using HR-TEM to estimate the sizes of the Pd nanoparticles. Complex [Pd(ONO)((N-benzylcarbamothioyl)benzamide)] (1) which does not possess any substituent on the benzyl moiety of acylthiourea produced the smallest Pd nanoparticles with the average particle size of 3.7?nm. Hence, complex 1 showed the utmost catalytic activity. With complex 1, 51–99% of conversion was observed during Heck coupling reaction of styrene with various aryl halides. XPS results confirmed that the recovered black particles were Pd(0). A reasonable recyclability results were achieved by these in situ generated Pd nanoparticles. Graphic Abstract: [Figure not available: see fulltext.]
Room temperature Z-selective hydrogenation of alkynes by hemilabile and non-innocent (NNN)Co(ii) catalysts
Gonnade, Rajesh G.,Gouda, Chandrakant,Punji, Benudhar,Sharma, Dipesh M.
, p. 1843 - 1849 (2022/04/07)
Hemilabile and phosphine-free quinolinyl-based NNN-type pincer and non-pincer cobalt complexes were developed for the room temperature catalytic transfer semi-hydrogenation of alkynes to Z-alkenes. Treatment of the quinolinyl-amine ligand, [C9H6N(NH)CH2CH2NEt2] (QNNNCH2NEt2)-H with CoX2 afforded the pincer complexes κ3-(QNNNCH2NEt2)CoX2 (X = Cl, Br), whereas, the quinolinyl-amide ligand, [C9H6N(NH)C(O)CH2NEt2] (QNNNC(O)NEt2)-H gave chelate anionic complexes κ2-(QNN)CoX2(NC(O)HNEt2) (X = Cl, Br). The well-defined anionic non-pincer cobalt complexes efficiently catalyzed the semi-hydrogenation of diverse alkynes to deliver highly chemoselective and stereodivergent Z-alkenes at room temperature. This hydrogenation exhibited broad substrate scope with the tolerance of sensitive functional groups, such as -Cl, -Br, -I, -OH, -NH2, -COOMe, and pyridinyl, employing a stable and user-friendly ammonia borane hydrogen source.
Electrochemical Proton Reduction over Nickel Foam for Z-Stereoselective Semihydrogenation/deuteration of Functionalized Alkynes
Valiente, Alejandro,Martínez-Pardo, Pablo,Kaur, Gurpreet,Johansson, Magnus J.,Martín-Matute, Belén
, (2021/12/22)
Selective reduction strategies based on abundant-metal catalysts are very important in the production of chemicals. In this paper, a method for the electrochemical semihydrogenation and semideuteration of alkynes to form Z-alkenes was developed, using a simple nickel foam as catalyst and H3O+ or D3O+ as sources of hydrogen or deuterium. Good yields and excellent stereoselectivities (Z/E up to 20 : 1) were obtained under very mild reaction conditions. The reaction proceeded with terminal and nonterminal alkynes, and also with alkynes containing easily reducible functional groups, such as carbonyl groups, as well as aryl chlorides, bromides, and even iodides. The nickel-foam electrocatalyst could be recycled up to 14 times without any change in its catalytic properties.
METHODS OF ARENE ALKENYLATION
-
Page/Page column 18; 24; 52-53; 62, (2021/11/26)
The present disclosure provides for a rhodium-catalyzed oxidative arene alkenylation from arenes and styrenes to prepare stilbene and stilbene derivatives. For example, the present disclosure provides for method of making arenes or substituted arenes, in particular stilbene and stilbene derivatives, from a reaction of an optionally substituted arene and/or optionally substituted styrene. The reaction includes a Rh catalyst or Rh pre-catalyst material and an oxidant, where the Rh catalyst or Rh catalyst formed Rh pre-catalyst material selectively functionalizes CH bond on the arene compound (e.g., benzene or substituted benzene).
