644-08-6Relevant academic research and scientific papers
Polymeric 2,2′-biquinolyl-containing NiII complexes as catalysts for the Suzuki reaction
Magdesieva,Nikitin,Polyakova,Yakimansky,Goikhman,Podeshvo
, p. 1193 - 1198 (2012)
The Suzuki reaction with polymeric Ni catalysts based on the biquinolyl-containing polyamic acids can be carried out under conditions close to the conditions used for the catalytic transformations in the presence of PdII complexes with the same polymeric ligands. However, the yields of the cross-coupling products on the Ni catalysts are somewhat lower than those obtained in the presence of palladium complexes. The yield of the cross-coupling product increases with the increase in the conformational mobility of the polymeric ligand. Unlike catalysis by palladium complexes, in catalytic transformations by nickel complexes activation of the catalyst is required. Such an activation can be carried out either by addition of chemical reducing agents or by applying the corresponding cathodic potential (-0.8 V relative to Ag/AgCl/KCl). The electrochemical activation was shown to lead to higher yields of the cross-coupling product than the use of chemical reducing agents.
Mercaptoaryl-Oxazoline Complexes of Palladium and Their High Activities as Catalysts for Suzuki–Miyaura Coupling Reactions in Water
Holzer, Christof,Dupé, Antoine,Peschel, Lydia M.,Belaj, Ferdinand,M?sch-Zanetti, Nadia C.
, p. 568 - 575 (2018)
The synthesis, spectroscopic characterization, and catalytic activities of a series of PdII complexes bearing the monoanionic, bidentate ligand 2-(2-thiophenyl)-4,4-dimethyloxazoline (S-Phoz) are reported. These complexes were used as precatalysts for Suzuki–Miyaura coupling reactions under aqueous conditions. The dimers [{PdX(S-Phoz)}2] (X = Cl, Br, I; 1–3) were treated with the N-heterocyclic carbene (NHC) ligand 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes) to afford the mononuclear complexes [PdX(S-Phoz)(IMes)] (X = Cl, Br, I; 4–6). The σ-donor/π-acceptor complexes [PdCl(S-Phoz)(EPh3)] (E = P, As, Sb; 7–9) were synthesized to evaluate the influence of a second donor ligand on the catalytic activity. Within the [PdCl(S-Phoz)L] series, the activity trend for L follows the trend PPh3 > IMes ≈ AsPh3 > SbPh3. The sulfur-bridged dinuclear complexes 1–3 are highly active for the benchmark coupling of p-bromoacetophenone with phenylboronic acid and exhibit turnover frequencies (TOFs) of up to 16000 h–1. DFT and G0W0 calculations were performed to rationalize the facile reduction and, hence, excellent activities of the dinuclear complexes.
Pd-Co3[Co(CN)6]2 hybrid nanoparticles: Preparation, characterization, and challenge for the Suzuki-Miyaura coupling of aryl chlorides under mild conditions
Li, Ren,Li, Ran,Wang, Changlai,Gao, Lei,Chen, Qianwang
, p. 539 - 544 (2015)
Because of their abundance and low cost, organo chlorides are the most desirable substrates from the industrial point of view in Suzuki-Miyaura cross-coupling reactions. However, catalytic application of Pd nanoparticles (NPs) for Suzuki coupling of aryl chlorides is still a challenge. Here, we design a novel catalyst by combining Pd NPs with Co3[Co(CN)6]2 nanocrystals for Suzuki-Miyaura coupling of aryl chlorides. This nanocatalyst demonstrated good activity (yield 86.2% at 80 °C), high TOF, great stability, easy separation, excellent reusability (initial rates were not reduced after five cycles) and low cost in Suzuki reactions.
Suzuki-Miyaura coupling reactions using novel metal oxide supported ionic palladium catalysts
Lichtenegger,Maier,Hackl,Khinast,G?ssler,Griesser,Kumar, V.S. Phani,Gruber-Woelfler,Deshpande
, p. 39 - 51 (2017)
Palladium substituted CeO2, SnO2 and their mixed oxides have been synthesized in quantitative yields out of non-toxic and inexpensive precursors using a simple and rapid single step solution combustion method. The resulting oxides, especially the mixed oxides Ce0.79Sn0.20Pd0.01O2-δ, Sn0.79Ce0.20Pd0.01O2-δ and Sn0.99Pd0.01O2-δ proved to be highly active (TOF > 12,000 h?1) for Suzuki-Miyaura cross-couplings of phenylboronic acid with various bromoarenes. The reactions were carried out in ambient air at moderate temperatures using environmentally friendly aqueous ethanol solutions as reaction solvents. Minimal amounts of palladium in the product solution ( 0.14 mg/L), the reaction kinetics as well as catalyst poisoning tests support the thesis that the reaction proceeds via dissolved palladium species in a homogeneous reaction mechanism. Nevertheless, the synthesized catalysts could be reused for at least five times with only minor changes in activity and no changes in the crystal structure, indicating the high potential of the investigated catalysts as quasi-heterogeneous C[sbnd]C coupling catalysts.
C-Br activation of aryl bromides at Ni0(NHC)2: Stoichiometric reactions, catalytic application in Suzuki-Miyaura cross-coupling, and catalyst degradation
Zell, Thomas,Fischer, Peter,Schmidt, David,Radius, Udo
, p. 5065 - 5073 (2012)
Complex [Ni2(iPr2Im)4(COD)] (1) (iPr2Im = 1,3-diisopropylimidazolin-2-ylidene) is a very efficient catalyst for the Suzuki-Miyaura cross-coupling reaction of 4-bromotoluene with phenylboronic acid and also mediates the Ullmann-type homo-cross-coupling reaction of bromobenzene with a moderate efficiency. Stoichiometric reactions of complex 1 with aryl bromides (ArBr) at room temperature lead to mixtures of aryl bromo complexes of the type trans-[Ni( iPr2Im)2(Br)(Ar)] and the bis(bromo) complex trans-[Ni(iPr2Im)2(Br)2] 2. The complexes trans-[Ni(iPr2Im)2(Br)(Ar)] (for Ar = Ph 3, 4-MeC6H44, 4-Me(O)CC6H45, 4-MeOC6H46, 4-MeSC6H47, 4-Me 2NC6H48, 2-C5NH49) can be selectively synthesized by working at low temperatures and using a high dilution of the starting materials. A major deactivation pathway for trans-[Ni(iPr2Im)2(Br)(Ar)] was identified in the presence of aryl bromides. This deactivation process includes (i) the formation of trans-[Ni(iPr2Im)2(Br) 2] from trans-[Ni(iPr2Im)2(Br)(Ar)] (2) and ArBr and (ii) the formation of an imidazolium salt of the type 2[ iPr2Im-Ar]+[NiBr4]2- from trans-[Ni(iPr2Im)2(Br)2] (2) and ArBr. The reactions of complex 2 with a series of aryl halides at higher temperatures lead to the decomposition of the bis(carbene) nickel moiety with formation of the imidazolium salts 2[iPr2Im-Ar] +[NiBr2X2]2- (for X = I, Ar = Ph 10 and X = Br, Ar = Ph 11, 4-MeC6H412, 4-FC6H 413, 4-OSi(CH3)3-C6H414) in high yields.
An efficient and reusable catalyst for Suzuki cross-coupling reactions in aqueous solution - Hollow palladium-ferrum bimetallic magnetic spheres
Liu, Mengmeng,Zhu, Xiaohang,Wu, Li,Zhou, Xingchun,Li, Jing,Ma, Jiantai
, p. 38264 - 38270 (2015)
Hollow Pd-Fe bimetallic magnetic spheres are synthesized in this work. Such materials are successfully characterized by ICP-AES, XPS, TEM, BET, XRD, and VSM, etc. These as-prepared hollow materials have high catalytic activity during Suzuki cross-coupling reactions between aryl halides and arylboronic acids in water. Meanwhile, the catalytic activity can be adjusted via changing the composition of the catalyst. The enhanced activity was attributed to both the hollow chamber structure and the promotional effect of Fe-dopants, which provided more Pd active sites during the reaction. Besides, due to the incorporation of ferrum, the recycling processes of the magnetic catalyst became simpler and more efficient.
Synthesis of brominated bisamides and their application to the suzuki coupling
Nobre, Sabrina M.,Cavalheiro, Valeria M.S.,Duarte, Leonardo S.
, p. 594 - 599 (2018)
Two brominated bisamides were developed by this protocol. Compounds were synthesized either by 4-bromobenzoyl chloride and ethylenediamine or by ortho-phenylenediamine. The choice of the diamine led to the desired products, which were characterized by IR,
Benzimidazolyl based Schiff base palladium complex in an ionic liquid: an effective combination for Suzuki coupling
Basappa Chidananda, Vasantha Kumar,Ramakrishna, Dileep,Kaur, Manpreet,Hosakere Doddarevanna, Revanasiddappa
, p. 1573 - 1584 (2017)
A new benzimidazole based Pd(II) Schiff base complex was prepared and its catalytic activity was evaluated for Suzuki cross-coupling reactions in ethyl-methyl imidazolium hexafluorophosphate [EMIM PF6] ionic liquid at ambient temperature. The system provides a stable and reusable method for coupling reactions. Optimization for suitable reaction conditions were studied with respect to the effect of catalyst concentration, effects of additives, solvent and substituents on boronic acid. Good to excellent yields were achieved using a modest amount of the catalyst. The reaction time was less and the yield was more compared to previously reported results. In addition, the catalyst can be easily reused and recycled for six times without much loss in activity; this is an example of sustainable and green methodology.
(Ni,Mg)3Si2O5(OH)4 solid-solution nanotubes supported by sub-0.06 wt % palladium as a robust high-efficiency catalyst for Suzuki-Miyaura cross-coupling reactions
Zhu, Wancheng,Yang, Yan,Hu, Shi,Xiang, Guolei,Xu, Biao,Zhuang, Jing,Wang, Xun
, p. 6020 - 6031 (2012)
(Ni1-x,Mgx)3Si2O 5(OH)4 solid-solution nanotubes (NTs) with tunable compositions were hydrothermally synthesized by altering the molar ratio of Mg2+ to Ni2+. The as-synthesized NTs were loaded with sub-0.06 wt % palladium (Pd; ～0.045 wt %) for Suzuki-Miyaura (SM) coupling reactions between iodobenzene or 4-iodotoluene and phenylboronic acid. The (Ni,Mg)3Si2O5(OH)4 (Mg 2+:Ni2+ = 1.0:1.0) NTs supported by 0.045 wt % Pd promoted the iodobenzene-participated coupling reaction with a high yield of >99%, an excellent recycling catalytic performance during 10 cycles of catalysis with yields of ～99%, and also an extremely low Pd releasing level of ～0.02 ppm. High-activity Pd and PdO clusters, multitudes of dislocations, and defects and terraces contained within the NTs should contribute to the (Ni,Mg) 3Si2O5(OH)4 (Mg2+:Ni 2+ = 1.0:1.0) NTs supported by 0.045 wt % Pd as a robust, reusable, and high-efficiency catalyst for SM coupling reactions with an extremely low Pd releasing level. The present hydrothermally stable (Ni,Mg)3Si 2O5(OH)4 (Mg2+:Ni2+ = 1.0:1.0) solid-solution silicate NTs provided an ideal alternative tubular-structured support for noble- or transition-metal catalysts with low Pd loading, good recycling, and extremely low ppb levels of Pd release, which could also be extended to some other SM coupling reactions.
Core-shell structured magnetic mesoporous silica supported Schiff-base/Pd: An efficacious and reusable nanocatalyst
Shaker, Masoumeh,Elhamifar, Dawood
, p. 3445 - 3454 (2020)
In this research, a novel Schiff-base/palladium complex containing magnetic ordered mesoporous silica (Fe3O4@MCM-41-SB/Pd) material with a core-shell structure is prepared and characterized, and its catalytic application is developed. The Fe3O4@MCM-41-SB/Pd nanocatalyst was characterized using FT-IR, TGA, SEM, VSM, PXRD and energy-dispersive X-ray (EDX) spectroscopy. This nanocatalyst showed high performance in the Suzuki cross-coupling reaction under ultrasonic conditions and delivered the corresponding products in high to excellent yield. The recovery study of the nanocatalyst proved that its activity is maintained during several stages of reuse. Moreover, the high stability of palladium species on the core-shell surface was confirmed by leaching and poisoning tests.
