346586-17-2Relevant academic research and scientific papers
Controlling olefin isomerization in the heck reaction with neopentyl phosphine ligands
Lauer, Matthew G.,Thompson, Mallory K.,Shaughnessy, Kevin H.
, p. 10837 - 10848 (2014)
The use of neopentyl phosphine ligands was examined in the coupling of aryl bromides with alkenes. Di-tert-butylneopentylphosphine (DTBNpP) was found to promote Heck couplings with aryl bromides at ambient temperature. In the Heck coupling of cyclic alkenes, the degree of alkene isomerization was found to be controlled by the choice of ligand with DTBNpP promoting isomerization to a much greater extent than trineopentylphosphine (TNpP). Under optimal conditions, DTBNpP provides high selectivity for 2-aryl-2,3-dihydrofuran in the arylation of 2,3-dihydrofuran, whereas TNpP provided high selectivity for the isomeric 2-aryl-2,5-dihydrofuran. A similar complementary product selectivity is seen in the Heck coupling of cyclopentene. Heck coupling of 2-bromophenols or 2-bromoanilides with 2,3-dihydrofurans affords 2,5-epoxybenzoxepin and 2,5-epoxybenzazepins, respectively.
Highly active homoleptic nickel(II) bis-N-heterocyclic carbene catalyst for Suzuki–Miyaura and Heck cross-coupling reactions
Nirmala, Muthukumaran,Arruri, Sathyanarayana,Vaddamanu, Moulali,Karupnaswamy, Ramesh,Mannarsamy, Maruthupandi,Adinarayana, Mannem,Ganesan, Prabusankar
supporting information, p. 125 - 134 (2018/11/23)
New homoleptic nickel(II) biscarbene complex was synthesized and structurally characterized. The complex depicted the excellent catalytic activities with only 3 mol% catalyst loading along with wide substrate scope for the Suzuki–Miyaura cross-coupling reactions (twenty six examples) and Heck coupling reactions (eighteen examples).
Mizoroki–Heck Cross-Coupling of Acrylate Derivatives with Aryl Halides Catalyzed by Palladate Pre-Catalysts
Islam, Mohammad Shahidul,Nahra, Fady,Tzouras, Nikolaos V.,Barakat, Assem,Cazin, Catherine S. J,Nolan, Steven P.,Al-Majid, Abdullah Mohammed
supporting information, p. 4695 - 4699 (2019/11/13)
The Mizoroki–Heck (MH) reaction involving aryl halides with various acrylates and acrylamides has been studied using air and moisture-stable imidazolium-based palladate pre-catalysts. These pre-catalysts can be converted into Pd-NHC species (NHC = N-heterocyclic carbene) under catalytic conditions and are capable of facilitating the Mizoroki–Heck reaction of aryl halides with various acrylates. The effects of solvent, catalyst loading, temperature and bases on the reaction outcome have been investigated. Various coupling partners were tolerated under the optimal reaction conditions catalyzed by palladate 1, [SIPr·H][Pd(η3-2-Me-allyl)Cl2]. The efficiency of the optimized synthetic methodology was tested on various aryl halides and substituted acrylates as well as acrylamides. The MH reaction yielded the coupled products in good to excellent isolated yields (up to 98%).
Synthesis of a novel ZnO nanoplates supported hydrazone-based palladacycle as an effective and recyclable heterogeneous catalyst for the Mizoroki-Heck cross-coupling reaction
Nouri, Fatemeh,Rostamizadeh, Shahnaz,Azad, Mohammad
, p. 664 - 673 (2017/12/15)
A new hydrazone-based palladacycle complex was successfully prepared onto ZnO nanoplates support and was fully identified by using a variety of methods such as energy dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller analysis (BET), inductively coupled plasma technique (ICP), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The morphology of nanoplates support has been also confirmed by scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). Furthermore, it was shown that ZnO nanoplates supported hydrazone-based palladacycle can act as a highly efficient heterogeneous catalyst for the Mizoroki-Heck cross-coupling reaction with excellent yields. The reaction was successfully carried out between aryl iodides, bromides or even aryl chlorides with a variety of olefins. Additionally, it is possible to isolate the catalyst from the reaction mixture and reused for eight sequential cycles without remarkable decrease in catalytic activity.
Synthesis and Characterization of C, C -Type Palladacycles and Their Catalytic Application in Mizoroki-Heck Coupling Reaction
Lo, Chi Hou,Lee, Hon Man
, p. 1150 - 1159 (2018/04/17)
Two series of ligand precursors, based on imidazo[1,2-a]pyridine and C2-phenyl substituted imidazole moieties, were developed and synthesized in high yields, featuring an N-CH2(C=O)Ar substituent on the imidazole ring. Upon reacting with palladium acetate, both series of ligands underwent double C-H bond activations at the methylene and o-aryl carbon sites on the N-CH2(C=O)Ar substituent, yielding C,C-type palladacycles bearing five-membered chelate rings. A dimeric palladium complex with bridging bromides was obtained from the ligand precursor with the bromide anion, whereas an ionic palladium complex with two "throw away" pyridine ligands was formed with the precursor of the tetrafluoroborate anion. All complexes are air-stable and were characterized by 1H and 13C NMR spectroscopy and elemental analysis. The structures of three of the new complexes were further established by single-crystal X-ray diffraction studies. These complexes have been screened for catalyzing Mizoroki-Heck coupling reaction using ionic salt as solvent. The complex based on imidazo[1,2-a]pyridine, which has an electron-donating 4-methoxyphenyl ring on the ligand scaffold, was the most efficient catalyst, capable of using activated aryl chloride and sterically hindered aryl bromide as substrates. It was also successfully applied in the green process of one-pot Mizoroki-Heck coupling/trans-esterification reaction in molten ionic salt.
A practical method for heterogeneously-catalyzed Mizoroki–Heck reaction: Flow system with adjustment of microwave resonance as an energy source
Ichikawa, Tomohiro,Mizuno, Masahiro,Ueda, Shun,Ohneda, Noriyuki,Odajima, Hiromichi,Sawama, Yoshinari,Monguchi, Yasunari,Sajiki, Hironao
, p. 1810 - 1816 (2018/03/07)
The microwave-assisted and continuous-flow Mizoroki–Heck reaction using a heterogeneous palladium catalyst supported on the anion-exchange resin DIAION WA30 (7% Pd/WA30) is described. The microwave resonance is finely adjusted to 2.4 GHz according to the electric permittivity of the reaction medium for efficient heating. Organic solvents, such as acetonitrile, N,N-dimethylacetamide, and toluene, can be sufficiently heated even with a low intensity of microwave irradiation in a 7% Pd/WA30-packed, glass tube-shaped catalyst cartridge, which was designed based on the electric permittivity of the solvents. The catalyst cartridge can be continuously reused at least 5 runs without exchange.
Well-defined palladium(0) complexes bearing N-heterocyclic carbene and phosphine moieties: Efficient catalytic applications in the Mizoroki-Heck reaction and direct C-H functionalization
Lee, Jhen-Yi,Shen, Jiun-Shian,Tzeng, Ru-Jiun,Lu, I-Chen,Lii, Jenn-Huei,Hu, Ching-Han,Lee, Hon Man
, p. 10375 - 10388 (2016/07/06)
Two series of well-defined palladium(0) complexes with phosphine-functionalized N-heterocyclic carbene ligands were prepared. These complexes featured six- and seven-membered chelate rings in the two series. Among the seven-membered chelate complexes, those featuring the PCy2 moiety exhibited observable fluxional behavior on the NMR time scale, corresponding to the interchange between two sets of conformations. Most of these novel complexes were successfully structurally characterized by single-crystal X-ray diffraction studies. These two series of palladium(0) complexes were tested for their potential catalytic applications in two mechanistically distinct reactions, namely, Mizoroki-Heck coupling and direct C-H functionalization reactions. One of the six-membered chelate complexes was found to be an efficient pre-catalyst for mediating the coupling reactions between aryl chlorides and alkenes. The palladium(0) complex could also be effectively applied in the direct C-H functionalization reactions of aryl bromides with 1,2-dimethylimidazole.
Ruthenium(II)-Catalyzed Decarboxylative C-H Activation: Versatile Routes to meta-Alkenylated Arenes
Kumar, N. Y. Phani,Bechtoldt, Alexander,Raghuvanshi, Keshav,Ackermann, Lutz
supporting information, p. 6929 - 6932 (2016/06/13)
Ruthenium(II) bis(carboxylate)s proved highly effective for two decarboxylative C-H alkenylation strategies. The decarboxylation proceeded efficiently at rather low temperatures. The unique versatility of the decarboxylative ruthenium(II) catalysis is reflected in the oxidative olefinations with alkenes as well as the redox-neutral hydroarylations of alkynes. Two birds with one Ru: Ruthenium(II) catalysis enabled decarboxylative C-H olefinations by carboxylate assistance at low temperature. It is applicable to both alkenes for oxidative olefinations, as well as alkynes for redox-neutral hydroarylations. Neither silver nor copper salts are required and meta-substituted products can be accessed with this method.
Maghemite decorated with ultra-small palladium nanoparticles (γ-Fe2O3-Pd): Applications in the Heck-Mizoroki olefination, Suzuki reaction and allylic oxidation of alkenes
Rathi, Anuj K.,Gawande, Manoj B.,Pechousek, Jiri,Tucek, Jiri,Aparicio, Claudia,Petr, Martin,Tomanec, Ondrej,Krikavova, Radka,Travnicek, Zdenek,Varma, Rajender S.,Zboril, Radek
, p. 2363 - 2373 (2016/05/19)
A nanocatalyst comprising ultra-small Pd/PdO nanoparticles (57Fe M?ssbauer spectroscopy. The cost-effective catalyst could be easily separated from the reaction mixture by using an external magnet and reused four times without any loss of activity; chemical stability and recyclability aspects of the catalyst were investigated.
2-Hydroxy-1,10-phenanthroline vs 1,10-Phenanthroline: Significant ligand acceleration effects in the Palladium-Catalyzed Oxidative Heck reaction of arenes
Ying, Cheng-Hao,Yan, Shao-Bai,Duan, Wei-Liang
supporting information, p. 500 - 503 (2014/04/03)
A series of bidentate monoanionic nitrogen ligands were designed and applied in the Pd-catalyzed oxidative Heck reaction of arenes with alkenes. Significant ligand-accelerated effects were observed, and direct C-H functionalized products were formed in high yields with meta-selectivity.
