92-93-3Relevant articles and documents
Synthesis, structural characterization and catalytic activity of two N-heterocyclic carbene-phosphine palladium(II) complexes
Xu, Chen,Hao, Xin-Qi,Li, Zhen,Dong, Xin-Ming,Duan, Lu-Meng,Wang, Zhi-Qiang,Ji, Bao-Ming,Song, Mao-Ping
, p. 34 - 37 (2012)
Two new N-heterocyclic carbene (NHC)-phosphine palladium(II) complexes Pd(IMeo)PPh3I2 1 and Pd(IMeo) P(C6H 4-p-Me)3I2 2 (IMeo = 1,3-di-4-methoxyphenyl- imidazolin-2-ylidene) have been easil
Visual observation of redistribution and dissolution of palladium during the Suzuki-Miyaura reaction
MacQuarrie, Stephanie,Horton, J. Hugh,Barnes, Jack,McEleney, Kevin,Loock, Hans-Peter,Crudden, Cathleen M.
, p. 3279 - 3282 (2008)
(Chemical Presented) Now you see it, now you don't: A specially designed reactor that heats only a small area of Pd foil during a Suzuki-Miyaura coupling permits observation of the surface changes during the reaction. Dissolution of Pd occurs only in the heated zone, and only in the presence of aryl iodide, whereas deposition of Pd occurs preferentially on the unheated zones adjacent to the reactive zone. SEM and XPS are employed to probe the surface before and after reaction.
Palladium(II) complexes featuring bidentate pyridine-triazole ligands: Synthesis, structures, and catalytic activities for Suzuki-Miyaura coupling reactions
Jindabot, Sudarat,Teerachanan, Kriengkamol,Thongkam, Pech,Kiatisevi, Supavadee,Khamnaen, Tossapol,Phiriyawirut, Phairat,Charoenchaidet, Sumate,Sooksimuang, Thanasat,Kongsaeree, Palangpon,Sangtrirutnugul, Preeyanuch
, p. 35 - 40 (2014)
Preparation of the Pd(II) complexes containing 2-(4-R-1,2,3-triazol-1-yl) pyridine [R = C6H5 (1), NC5H4 (2), n-C6H13 (3)] were described. Crystal structures of 1 and 2 revealed a square planar geometry with bidentate ligand coordination to Pd using different N donor of the triazole ring. Catalytic studies indicated that 1-3 exhibited moderate to high activity for Suzuki-Miyaura coupling between aryl bromides and phenylboronic acid under mild and aerobic conditions.
Catalytic cross-coupling reaction of aryl iodides with triarylbismuths by an N-heterocyclic carbene-PdCl2 based on benzo-9-crown-3 catalyst at room temperature
Liu, Jia-Qi,Yang, Jun-Juan,Li, Jun-Fei,Li, Kai,Xiao, Xue-Dong,Bai, Ya-Li,Wang, Jun-Wen
, p. 125 - 130 (2017)
We have developed the N-heterocyclic carbene ligand/PdCl2 catalyst for C[sbnd]C coupling reaction of aryl iodides and organobismuths at room temperature. The established catalytic system exhibited high cross-coupling reactivity between a variety of orgnobismuths and aryl iodides in the presence of K2CO3 as base in NMP or DMSO at room temperature. The simple and efficient transformation can tolerate either electron-withdrawing or electron-donating functional groups. It was notably found that both aryl bromide and aryl chloride generated moderate to good yields of the corresponding biphenyl products using 5 mol% of PPh3/ligand 5 (1:1) as catalyst.
Highly Efficient and Accelerated Suzuki Aryl Couplings Mediated by Phosphine-Free Palladium Sources
Wallow, Thomas I.,Novak, Bruce M.
, p. 5034 - 5037 (1994)
Suzuki aryl cross-couplings employing aryl bromides and aryl iodides proceed under mild conditions (65 deg C) with high efficiency (substrate-to-catalyst ratios in excess of 500) in the presence of phosphine-free palladium catalysts derived from palladium acetate, Pd2(dba)3*C6H6 (dba = dibenzylideneacetone), and 3-C3H5)PdCl>2.Phosphine inhibition is shown to play a key role in limiting catalytic efficiency; qualitative comparison studies show that the phosphine-free systems are 1-2 orders of magnitude more active than phosphine-supported catalytic systems.Pd4 proved to be the least active of the catalytic species screened.The phosphine-free methodology appears to be generally applicable; cross-couplings of aryl iodides yielding biaryls 6 and 7 proceed without noticeable steric or electronic effects.Cross-couplings employing aryl bromides are insensitive to electronic effects in the synthesis of 6 but are slowed by steric hindrance in the synthesis of 7.Acceleration of cross-coupling is observed in the presence of polar cosolvents and at high pH.
Pd nanocatalyst adorned on magnetic chitosan?N-Heterocyclic carbene: Eco-compatible suzuki cross-coupling reaction
Sedghi, Roya,Heidari, Bahareh,Shahmohamadi, Hatef,Zarshenas, Pourya,Varma, Rajender S.
, (2019)
A novel magnetic-functionalized-multi-walled carbon nanotubes?chitosan N-heterocyclic carbene-palladium (M-f-MWCNTs?chitosan-NHC-Pd) nanocatalyst is developed in two steps. The first step entails the fabrication of a three-component cross-linking of chitosan utilizing the Debus-Radziszewski imidazole approach. The second step comprised the covalent grafting of prepared cross-linked chitosan to the outer walls of magnetically functionalized MWCNTs (M-f-MWCNTs) followed by introducing PdCl2 to generate the m-f-MWCNTs?cross-linked chitosan with a novel NHC ligand. The repeated units of the amino group in the chitosan polymer chain provide the synthesis of several imidazole units which also increase the number of Pd linkers thus leading to higher catalyst effciency. The evaluation of catalytic activity was examined in the expeditious synthesis of biaryl compounds using the Suzuki cross-coupling reaction of various aryl halides and aryl boronic acids; ensuing results show the general applicability of nanocatalyst with superior conversion reaction yields, high turnover frequencies (TOFs) and turnover numbers (TON). Meanwhile, nanocatalyst showed admirable potential in reusability tests, being recycled for five runs without losing significant activities under optimum reaction conditions. The successfully synthesis of catalyst and its characterization was confirmed using the Fourier transform infrared spectrometer (FT-IR), spectrometer transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photo-electron spectroscopy (XPS) and thermogravimetric analysis (TGA).
Immobilization of palladium(II)-containing bis(imidazolium) ligand on ion-exchange resins: Efficient and reusable catalysts for C-C coupling reactions
Pahlevanneshan, Zari,Moghadam, Majid,Mirkhani, Valiollah,Tangestaninejad, Shahram,Mohammadpoor-Baltork, Iraj,Khosropour, Ahmad R.
, p. 346 - 352 (2015)
Suzuki reactions catalysed by a palladium(II) complex of a functionalized bis(imidazolium) ligand, PdII(BIM), immobilized on Dowex 50 WX8 and Amberlite IR-120 ion-exchange resins as heterogeneous, recyclable and active catalysts are reported. The catalysts, PdII(BIM)@Amberlite IR-120 and PdII(BIM)@Dowex 50 WX8, were characterized using Fourier transform infrared and diffuse-reflectance UV-visible spectroscopies and scanning electron microscopy. These heterogeneous catalysts are oxygen-insensitive and air- and moisture-stable in C-C coupling reactions, and are reusable several times without significant loss of their catalytic activity.
Palladium nanoparticles supported in a polymeric membrane: An efficient phosphine-free "green" catalyst for Suzuki-Miyaura reactions in water
Faria, Vinicius W.,Oliveira, Deyvid G. M.,Kurz, Marcia H. S.,Goncalves, Fabio F.,Scheeren, Carla W.,Rosa, Gilber R.
, p. 13446 - 13452 (2014)
Palladium(0) nanoparticles supported on a polymeric membrane, CA/Pd(0), were found to be a highly efficient "dip catalyst" (heterogeneous catalyst) for Suzuki-Miyaura cross-coupling reactions. Iodo-, bromo- and electron-poor chloroarenes coupled with phenylboronic acid under eco-friendly conditions (i.e., phosphine-free and with water as the solvent) to give excellent yields. The CA/Pd(0) was prepared initially via the synthesis of Pd(0) by hydrogen decomposition of Pd(acac)2 dissolved in BMI·BF4 ionic liquid at 75°C for 1.0 hour to yield a black suspension (nanoparticles with a diameter of 2.7 ± 0.4 nm). These nanoparticles were washed with acetone and dried under reduced pressure. The Pd(0) nanoparticles were subsequently added to a cellulose acetate solution with acetone to generate the CA/Pd(0) polymeric membrane. The CA/Pd(0) "dip catalyst" was characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron-dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). This journal is the Partner Organisations 2014.
Nickel stabilized by triazole-functionalized carbon nanotubes as a novel reusable and efficient heterogeneous nanocatalyst for the Suzuki-Miyaura coupling reaction
Hajipour, Abdol. R.,Abolfathi, Parisa
, p. 110622 - 110628 (2016)
An interesting nanotube based nickel nanocatalyst was successfully prepared through "click" reaction of azide-functionalized nanotube with propargyl alcohol followed by immobilization of nickel nanoparticles. The as-prepared nanocatalysts behave as very efficient heterogeneous catalysts in the Suzuki-Miyaura cross coupling reaction in terms of activity and recyclability.
An efficient clean and sustainable methodology for catalytic C-C coupling process over a Pd-free magnetically recoverable cobalt catalyst
Masteri-Farahani, Majid,Niakan, Mahsa
, (2022/03/27)
The Suzuki and Sonogashira coupling reactions are important processes in organic synthesis. However, to date, these reactions have been extensively examined using Pd-based catalysts in toxic organic solvents. Therefore, developing clean and inexpensive methodologies for these reactions remained a major challenge. Herein, by taking the advantages of thiol-ene click reaction, an easy and robust strategy for surface modification of magnetic graphene oxide with a dendrimer structure was successfully developed. Dendrimer-functionalized magnetic graphene oxide was then applied for the immobilization of Co nanoparticles. Transmission electron microscopy exhibited a homogeneous distribution of Co nanoparticles with the size of about 3 nm. The resultant nanocomposite revealed high efficiency in catalytic Suzuki and Sonogashira reactions in non-hazardous and sustainable deep eutectic solvents (DESs). The DES and catalyst were simply recycled five times with gradual slight decrease in the yield of the reactions. More importantly, the catalyst was magnetically isolated at the end of the recycling process. Overall, the utilization of DES as an environmentally friendly and recoverable reaction medium, as well as replacing the low-cost cobalt catalyst as an alternative to expensive Pd catalyst along with the facile catalyst isolation by employing an external magnetic field, make the present protocol promising from economic and green chemistry points of view for the clean C-C coupling reactions.
