- Pd supported on clicked cellulose-modified magnetite-graphene oxide nanocomposite for C-C coupling reactions in deep eutectic solvent
-
Cellulose-modified magnetite-graphene oxide nanocomposite was prepared via click reaction and utilized for immobilization of palladium (Pd) nanoparticles without using additional reducing agent. The abundant OH groups of cellulose provided the uniform dispersion and high stability of Pd nanoparticles, while magnetite-graphene oxide as a supporting material offered high specific surface area and easy magnetic separation. The as-prepared nanocomposite served as a heterogeneous catalyst for the Heck and Sonogashira coupling reactions in various hydrophilic and hydrophobic deep eutectic solvents (DESs) as sustainable and environmentally benign reaction media. Among the fifteen DESs evaluated for coupling reactions, the hydrophilic DES composed of dimethyl ammonium chloride and glycerol exhibited the best results. Due to the low miscibility of catalyst and DES in organic solvents, the separated aqueous phase containing both of the catalyst and DES can be readily recovered by evaporating water and retrieved eight times with negligible loss of catalytic performance.
- Karimi, Sabah,Masteri-Farahani, Majid,Niakan, Mahsa,Shekaari, Hemayat
-
-
- Palladium nanoparticles encapsulated in polyimide nanofibers: An efficient and recyclable catalyst for coupling reaction
-
In this study, palladium-encapsulated poly(amic acid) (Pd@PAA) nanofibers were prepared by electrospinning, followed by thermal imidization to synthesize palladium-encapsulated polyimide (Pd@PI) nanofibers. Scanning electron microscopy (SEM) images confirmed the preparation of uniform and smooth Pd@PAA and Pd@PI nanofibers. Thermogravimetric analysis (TGA) results reveal that the Pd@PI nanofibers possessed excellent thermal stability. The dispersion of palladium nanoparticles in the polyimide nanofibers was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The catalysis results show that this Pd@PI fibrous catalyst was very efficient to catalyze the cross-coupling reactions of aromatic iodides with n-butyl acrylate (Heck reaction) or phenylboronic acid derivatives (Suzuki reaction) to afford the desired products in good to excellent yields. Moreover, the Pd@PI catalyst could be easily separated and recovered from the reaction mixture by simple filtration due to the regular fibrous structure and reused for 10 times for both Heck and Suzuki reactions without obvious loss of its initial catalytic activity. Thus, the Pd@PI nanofiber catalyst holds great potential in chemical industry in terms of its excellent catalytic activity and stability.
- Du, Yijun,Gou, Faliang,Gao, Danning,Liu, Zhifeng,Shao, Linjun,Qi, Chenze
-
-
- Fe-MIL-101 modified by isatin-Schiff-base-Co: a heterogeneous catalyst for C-C, C-O, C-N, and C-P cross coupling reactions
-
A metal-organic framework functionalized with a cobalt-complex is preparedviapost-synthetic modification of Fe-MIL-101-NH2. Initially, Fe-MIL-101-NH2reacted with isatin to produce Fe-MIL-101-isatin-Schiff-base, which can anchor the cobalt by the addition of cobalt acetate. The resulting MOF-Co catalyst is characterized by employing multiple techniques. This new modified MOF acts as a heterogeneous and recyclable catalyst for efficient Ullmann, Buchwald-Hartwig, Hirao, Hiyama and Mizoroki-Heck cross-coupling reactions of several aryl halides/phenylboronic acid/phenyltosylate with phenols, anilines/heterocyclic amines, triethyl phosphite, triethoxyphenylsilane and alkenes and generates the expected coupling products in good to high yields.
- Farrokhi, Alireza,Rouzifar, Majid,Sansano, José Miguel,Sobhani, Sara
-
p. 19963 - 19976
(2021/11/12)
-
- Reusable, magnetic Raney nickel based palladium catalysts for the Heck coupling in aqueous media
-
Hybrid materials based on Pd- and Cu-doped Raney nickel appeared to be highly efficient catalysts for the Heck reaction in aqueous media in the absence of organic cosolvents. The catalysts can be easily removed by an external magnet and reused without losing catalytic activity.
- Bumagin, N. A.
-
p. 2034 - 2040
(2021/11/05)
-
- A comparative study of palladium-based coordination compounds with bidentate (N,N, P,P and P,O) ligands; Design, synthesis, X-ray structural, catalytic activity and DFT studies
-
This account describes our recent studies on four new asymmetric cyclometallated Pd(II) complexes with a formula [L1 → Pd ← L2](ClO4) (L1 = benzylamine and L2 = bis (diphenylphosphino) methane oxide (
- Babaee, Heshmatollah,Javad Sabounchei, Seyyed,Naghipour, Ali,Notash, Behrouz,Sayadi, Mohsen,Sedghi, Asieh
-
-
- Introduction of a Recyclable Basic Ionic Solvent with Bis-(NHC) Ligand Property and The Possibility of Immobilization on Magnetite for Ligand- and Base-Free Pd-Catalyzed Heck, Suzuki and Sonogashira Cross-Coupling Reactions in Water
-
A new versatile and recyclable NHC ligand precursor has been developed with ligand, base, and solvent functionalities for the efficient Pd-catalyzed Heck, Suzuki and Sonogashira cross-coupling reactions under mild conditions. Furthermore, NHC ligand precursor was immobilized on magnetite and its catalytic activity was also evaluated towards the coupling reactions as a heterogeneous catalyst. The NHC ligand precursor was prepared with imidazolium functionalization of TCT followed by a simple ion exchange by hydroxide ions. However, the results revealed an excellent catalytic activity for the both homogeneous and heterogeneous catalytic systems. 1.52?g.cm?3 and 1194 cP was obtained for the density and viscosity of the NHC ligand precursor respectively. On the other hand, the heterogeneous type could be readily recovered from the reaction mixture and reused for several times while preserving its properties. Heterogeneous nature of the magnetic catalyst was studied by hot filtration, mercury poisoning, and three-phase tests. High to excellent yields were obtained for all entries for the both homogeneous and heterogeneous catalysts, which reflects the high consistency of the catalyst. Graphic Abstract: [Figure not available: see fulltext.]
- Min, Qingwang,Miao, Penghua,Chu, Deyu,Liu, Jinghan,Qi, Meijuan,Kazemnejadi, Milad
-
p. 3030 - 3047
(2021/02/16)
-
- Palladium supported aminobenzamide modified silica coated superparamagnetic iron oxide as an applicable nanocatalyst for Heck cross-coupling reaction
-
An applicable palladium-based nanocatalyst was constructed through the immobilization of palladium onto 2-aminobenzamide functionalized silica coated superparamagnetic iron oxide magnetic nanoparticles. The nanocatalyst (named as Pd@ABA@SPIONs@SiO2) was characterized by several characterization methods, including scanning electron microscope (SEM), transmission electron microscopy (TEM), vibrating-sample magnetometry (VSM), energy-dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma (ICP), and X-ray photoelectron spectroscopy (XPS) analyses. Microscopy results showed that the nanoparticles are spherical in shape with 20–25 nm size. The size of the nanoparticles was confirmed by the DLS method. The superparamagnetic nature of the catalyst was confirmed by the VSM method. The successful functionalization of SPIONs@SiO2 was confirmed by FT-IR spectroscopy. The presence of palladium in the structure of the nanocatalyst was illustrated by XRD and EDS analysis. Also using XPS technique, the oxidation state of palladium in Pd@ABA@SPIONs@SiO2 was determined zero before and after the catalyst was applied in Mizoroki-Heck reaction. Several aryl halides and alkenes were reacted in the presence of the nanocatalyst and formed the corresponding products in high isolated yields. The nanocatalyst showed very good reusability and did not decrease its activity after 10 sequential runs. Density functional theory (DFT) calculation was performed to provide a mechanism for the reaction and confirmed the role of the palladium catalyst in the reaction function.
- Fatahi, Yousef,Ghaempanah, Aram,Ma?mani, Leila,Mahdavi, Mohammad,Bahadorikhalili, Saeed
-
-
- A new palladium heterogeneous complex (Pd-Gu@BOEH): chemoselective, phosphine-free and practical nanocatalyst in carbon–carbon cross-coupling reaction
-
Herein, boehmite nanoparticles were synthesized via combination of Al(NO3)3·9H2O and NaOH in aqueous solution. This nanomaterial converted to Pd-Gu@BOEH in several sequences. Pd-Gu@BOEH was used as efficient and recoverable nanocatalyst for the chemoselective C–C band formation such as Mizoroki–Heck and Suzuki–Miyaura reactions without any phosphine ligands or inert atmosphere. This catalyst has been characterized by several analyses such as EDS, WDX, SEM, XRD, FT-IR, TEM, TGA, AAS and BET. Also, obtained products from C–C coupling reactions were identified by NMR spectroscopy and their melting points. This catalyst was recycled in described reactions without palladium leaching. The reused catalyst was characterized by EDS, WDX, XRD, FT-IR and AAS analysis, which showed good stability during reaction process.
- Jafari, Fariba,Ghorbani-Choghamarani, Arash,Hasanzadeh, Neda
-
p. 1033 - 1049
(2020/11/05)
-
- A hydrophilic heterogeneous cobalt catalyst for fluoride-free Hiyama, Suzuki, Heck and Hirao cross-coupling reactions in water
-
A hydrophilic heterogeneous cobalt catalyst of chitosan, denoted as mTEG-CS-Co-Schiff-base, has been successfully prepared. This newly synthesized catalyst was characterized by different methods such as XRD, FE-SEM, TEM, TGA, FT-IR, 13C{1H} CP/MAS NMR, XPS and ICP analyses. The catalyst displayed excellent activity for the palladium and fluoride-free Hiyama, Suzuki, Heck and Hirao reactions of various aryl iodides, bromides and chlorides (i.e., the most challenging aryl halides which are cheaper and more widely available than aryl iodides and bromides) in water. The presence of triethylene glycol tags with hydrophilic character on the Co-complex supported on chitosan provides dispersion of the catalyst particles in water, which leads to higher catalytic performance and also facile catalyst recovery by successive extraction. It was reused for at least six successive runs without any discernible decrease in its catalytic activity or any remarkable changes in catalyst structure. The use of water as a green solvent, without requiring any additive or organic solvent, as well as use of a low cost and abundant cobalt catalyst instead of expensive Pd catalysts along with the catalyst recovery and scalability, make this method favorable from environmental and economic points of view for the C-C and C(sp2)-P coupling reactions. Notably, this is the first report on the application of a cobalt catalyst in Hiyama reactions.
- Sobhani, Sara,Hosseini Moghadam, Hadis,Skibsted, J?rgen,Sansano, José Miguel
-
p. 1353 - 1365
(2020/03/11)
-
- Palladium schiff base complex immobilized on magnetic nanoparticles: An efficient and recyclable catalyst for Mizoroki and Matsuda-Heck coupling
-
The present work elucidates the catalytic efficiency of palladium Schiff base complex immobilized on amine functionalized magnetic nanoparticles for Heck coupling of structurally different aryl halide/arenediazonium tetrafluoroborate with styrene/acrylate/acrylonitrile. Matsuda-Heck coupling proceeds in aqueous media at room temperature whereas Mizoroki-Heck coupling was carried out at 80 °C. Both reactions were successfully furnished with low catalyst loading. The catalyst was easily separated from reaction mixture and reused up to six times without significant loss of catalytic activity.
- Vibhute, Sandip P.,Mhaldar, Pradeep M.,Shejwal, Rajendra V.,Rashinkar, Gajanan S.,Pore, Dattaprasad M.
-
supporting information
(2020/03/23)
-
- Encapsulating palladium nanoparticles inside ethylenediamine functionalized and crosslinked chlorinated poly(vinyl chloride) nanofibers as an efficient and stable heterogeneous catalyst for coupling reactions
-
Palladium chloride and chlorinated poly (vinyl chloride) (CPVC) mixture were prepared into homogeneous solution, followed by electrospinning to make uniform nanofibers with average diameter of ~460 nm. Then, these composite nanofibers were treated in ethy
- Du, Yijun,Qi, Chenze,Qin, Min,Shao, Linjun,Tao, Hongyu,Wang, Qingqing
-
-
- Air-Stable Fe3O4@SiO2-EDTA-Ni(0) as an Efficient Recyclable Magnetic Nanocatalyst for Effective Suzuki-Miyaura and Heck Cross-Coupling via Aryl Sulfamates and Carbamates
-
The synthesis of inexpensive and novel air-stable Ni(0) nanoparticles immobilized on the EDTA-modified Fe3O4@SiO2 nanocatalyst was investigated in Suzuki-Miyaura and Heck cross-coupling reactions. This catalytic system displayed a greatly improved substrate scope for the carbon–carbon bond formations starting from a wide range of green and economical electrophiles aryl and heteroaryl carbamates and sulfamates via highly efficient method under mild, operationally simple reaction conditions. The synthesized heterogeneous catalyst was also fully characterized by FT-IR, TEM, XRD, DLS, FE-SEM, UV–Vis, EDX, XPS, TGA, NMR, VSM, ICP and elemental analysis techniques. The heterogeneous magnetic nanocatalyst can easily be recovered by an external magnetic field and reused for the next reactions for at least seven times with negligible leaching of catalyst and no substantial decrement in the activity. All these highlights have made the present protocol an interesting, simple and environmentally benign process with low catalyst loading and easy manipulations.
- Dindarloo Inaloo, Iman,Majnooni, Sahar,Eslahi, Hassan,Esmaeilpour, Mohsen
-
-
- Promising new catalytic properties of a Co (II)-carboxamide complex and its derived Co3O4 nanoparticles for the Mizoroki-Heck and the Epoxidation reactions
-
The new Co(II) - carboxamide complex (1) and Co3O4 nanoparticles (2), by way of thermal decomposition of (1) have been efficiently synthesised in the environment-friendly. X-ray diffraction reveals a slightly distorted octahedral coordination of cobalt (four nitrogens and two oxygens) in (1) and regular octahedral or tetrahedral ones (oxygens only) in (2). The investigation of (1) and (2) in the Mizoroki-Heck and epoxidation of alkens reactions showed them both to be powerful, green and inexpensive catalysts.
- Kiani, Mahsa,Bagherzadeh, Mojtaba,Meghdadi, Soraia,Fadaei-Tirani, Farzaneh,Babaie, Maryam,Schenk-Jo?, Kurt
-
-
- A new approach to large scale production of dimethyl sulfone: A promising and strong recyclable solvent for ligand-free Cu-catalyzed C-C cross-coupling reactions
-
Dimethyl sulfone (DMSN) was easily prepared through efficient oxidation of dimethyl sulfoxide (DMSO) and used as a strong and green solvent for organic reactions. A mixture of HNO3/NaOCl was used as an oxidizing agent for efficient oxidation of DMSO to DMSN. The effect of DMSN was evaluated for copper-catalyzed coupling reactions. It is worth noting that DMSN could play the role of a ligand for copper ions. A general survey was accomplished for various types of C-C cross-coupling reactions catalyzed by CuI in DMSN in the absence of any ligand. Moderate to good yields were achieved for Sonogashira, Heck, and Suzuki cross-coupling reactions. Finally, DMSN was recovered and reused for several consecutive runs without any loss of its activity.
- Cheng, Shen,Wei, Wei,Zhang, Xingyu,Yu, Hewei,Huang, Mingming,Kazemnejadi, Milad
-
p. 2069 - 2076
(2020/04/07)
-
- A highly efficient palladium complex supported on MCM-41 nanocatalyst for Mizoroki–Heck and Suzuki–Miyaura cross-coupling reaction
-
Palladium-3,4-dihydroxybenzaldehyde complex supported on MCM-41 was synthesized by a post-grafting method as selective complex a and shows remarkable properties such as thermal and chemical stability, reusable, easily prepared from very cheap materials and can be used as an efficient and versatile catalyst for Mizoroki–Heck and Suzuki–Miyaura cross-coupling reaction. This catalyst was characterized by SEM, TEM, EDX, XRD, FT-IR, TGA, BET and ICP techniques. The synthesized Pd-BS-MCM-41 heterogeneous catalyst could be recovered easily and reused several times without significant loss of its catalytic activity. Further investigations showed that among different aryl halides that used for the synthesis of biaryls and butyl cinnamate derivatives, the reactivity of aryl iodides is higher than aryl bromides, and aryl chlorides. The heterogeneity manner of this nanocatalyst was confirmed via a hot filtration test.
- Nikoorazm, Mohsen,Khanmoradi, Maryam,Abdi, Zahra
-
p. 2577 - 2585
(2020/06/03)
-
- Polyoxometalate-supported Pd nanoparticles as efficient catalysts for the Mizoroki-Heck cross-coupling reactions in PEG medium
-
Palladium nanoparticles supported on polyoxometalate as a solid carrier were successfully prepared and evaluated as a heterogeneous nanocatalyst for the Mizoroki-Heck cross-coupling reactions. This supported catalyst was characterized by a set of techniques, including XRD, chemical analysis (ICP-OES), IR spectroscopy, TEM and FE-SEM analyses. Poly (ethylene glycol) was employed as an environmentally friendly solvent for coupling reactions. The various fundamental reaction parameters that influence the efficiency of the reaction and yield of the desired reaction products were optimized. This catalytic system showed good activities and evolve a strategy for achieving five times catalyst and green solvent recyclability without appreciable loss of its activity, thus making this protocol eco-friendly.
- Bagherzadeh, Mojtaba,Hosseini, Hadighehsadat,Salami, Rasoul
-
-
- L-Methionine-Pd complex supported on hercynite as a highly efficient and reusable nanocatalyst for C-C cross-coupling reactions
-
A "green" method was suggested for the synthesis of hercynite magnetic nanoparticles (MNPs) as a novel heterogeneous catalytic support to immobilize homogeneous complexes. l-Methionine-Pd was immobilized on the surface of hercynite MNPs by a simple, rapid, and convenient route. The structure and composition of the prepared Hercynite@l-Methionine-Pd MNPs were characterized by X-ray diffraction spectroscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma-optical emission spectrometry, scanning electron microscopy, X-ray mapping, thermogravimetric analysis and vibrating-sample magnetometry (VSM). Besides, they were applied as green nanocatalysts for Suzuki and Heck cross-coupling reactions. Hercynite@l-Methionine-Pd MNPs offer several advantages (simple synthetic method under green conditions, thermal and chemical stability during organic reactions, short reaction times, high yields of products, excellent selectivity and easy work-up procedure). Moreover, the recycled nanocatalyst was reused for at least five cycles with no significant loss of activity. The hot filtration test indicated heterogeneous catalysis for Suzuki and Heck cross-coupling reactions. This work is useful for the development and application of a magnetically recoverable Pd nanocatalyst on the basis of green-chemistry principles.
- Mohammadi, Masoud,Ghorbani-Choghamarani, Arash
-
supporting information
p. 2919 - 2929
(2020/03/03)
-
- Fe3O4-Lignin@Pd-NPs: A highly efficient, magnetically recoverable and recyclable catalyst for Mizoroki-Heck reaction under solvent-free conditions
-
Palladium nanoparticles (Pd-NPs) were synthesized under green conditions in water by chemical reduction of PdCl2 with NaOH and supported by Fe3O4-Lignin. Fe3O4-Lignin is an organic–inorganic hybrid core-shell was synthesized by sonication of a mixture of Fe3O4-NPs (20 nm) and alkali lignin. The new materials Fe3O4-Lignin and Fe3O4-Lignin@Pd-NPs were characterized by PXRD, SEM and FT-IR spectroscopy. The Fe3O4-Lignin@Pd-NPs was further confirmed by UV–Visible spectroscopy, TEM, EDX, HRICP-AES and TGA/DTA. The average size of Pd-NPs determined from PXRD was 5–10 nm. The amount of palladium loaded on Fe3O4-Lignin obtained from EDX analysis was 26.63percent by mass. The amount of Fe and Pd present in the catalyst obtained from HRICP-AES was 11.88 (wt. percent) and 10.90 (wt. percent) respectively per gram of lignin. The catalytic potential of Fe3O4-Lignin@Pd-NPs was evaluated in Mizoroki-Heck C-C coupling reaction. During the optimization studies of reaction between iodobenzene and n-butyl acrylate in various solvents and under solvent-free but aerobic conditions using various inorganic and organic bases, the product n-butyl 3-phenylprop-2-enoate (1a) obtained was as high as 95percent in highly polar solvents as short as in 10 min and 99percent under solvent-free conditions in 3 min at 140 °C using n-Pr3N as base. The scope of the above catalyst was investigated in the Mizoroki-Heck reaction of various aryl/heterocyclic halides and n-butyl acrylate/styrene under optimized solvent-less conditions. The corresponding products were obtained in high yields (73–99percent). The catalyst recovered by magnetic decantation was reused for five times in the C-C coupling reaction between iodobenzene and n-butyl acrylate which yielded 90–95percent of the desired product, 1a.
- Madrahalli Bharamanagowda, Marulasiddeshwara,Panchangam, Raghavendra Kumar
-
-
- Biogenic synthesis of palladium nanoparticles using Boswellia sarrata and their applications in cross-coupling reactions
-
A facile and green route for biogenic synthesis of palladium nanoparticles (PdNPs) using aqueous extract of nontoxic and renewable Boswellia sarrata leaves is reported. The as-synthesized PdNPs were systematically characterized by using ultraviolet (UV)–visible spectroscopy, X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The PdNPs were crystalline and cubic in nature with average particle size of ~6 nm and successfully employed as heterogeneous catalyst in the Suzuki–Miyaura and Mizoroki–Heck cross-coupling reactions. The PdNPs could be recycled up to five times with modest change in the catalytic activity.
- Arde, Satyanarayan M.,Rashinkar, Gajanan S.,Jadhav, Sanjay N.,Patil, Audumbar D.,Salunkhe, Rajashri S.
-
-
- Multidentate N-Heterocyclic Carbene Complexes of Nickel and Palladium: Structural Analysis and Catalytic Application in Mizoroki–Heck Coupling Reaction
-
Two series of electron-rich metal (Ni and Pd) complexes, namely a pyridine-coordinated tridentate NHC/amidate/phenoxy metal complex and a tetradentate complex bearing an extra pyridyl group, were synthesized. Two carbene moieties, imidazole-based and benzimidazole-based NHCs, were also incorporated into the ligand backbones. Seven of the new complexes were structurally characterized and comparative structural analysis revealed that the tetradentate complex with a flanking pyridyl side-arm was less distorted, leading to chelation-assisted stronger NHC coordination and hence a shorter metal–carbene bond. The catalytic activities of the two sets of palladium complexes for the Mizoroki–Heck coupling reaction were investigated. The comparative data showed that despite the higher thermal stability and the presence of the flanking hemilabile pyridyl side-arm which provided unsaturation to the metal center, the catalytic performance was slightly inferior to that of the tridentate palladium complex with a “throw-away” pyridine ligand. The tridentate palladium complex with the benzimidazole-based NHC moiety was the most effective catalyst, allowing the utilization of a range of aryl chlorides including deactivated substrates with a low 0.2 mol-% Pd loading in molten n-tetrabutylammonium bromide.
- Liu, Li-Cheng,Tzeng, Yan-Hsiang,Hung, Cheng-Hau,Lee, Hon Man
-
p. 3601 - 3611
(2020/09/01)
-
- PdII Immobilized on Ferromagnetic Multi-Walled Carbon Nanotubes Functionalized by Aminated 2-Chloroethylphosphonic Acid with S -Methylisothiourea (FMMWCNTs@CPA@SMTU@PdII NPs) Applied as a Highly Efficient and Recyclable Nanostructured Catalyst for Suzuki-Miyaura and Mizoroki-Heck Cross-Coupling Reactions in Solvent-Free Conditions
-
The new ferromagnetic nanostructured FMMWCNTs@CPA@SMTU@PdII NPs (IV) as an eco-friendly heterogeneous nanocatalyst with a particle size of ~20-30 nm reported earlier by our group has been found to be very effective for Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions at ambient temperature. The procedure has been applied for a wide range of aryl halides, arylboronic acids, and alkenes. The magnetic separation by an external magnetic field, mild reaction conditions, and catalyst reusability up to four times without significant decrease in catalytic activity (reduced catalytic activity from 11 to 18 % in the fifth, sixth, and seventh cycles) made the present method sustainable and economically viable for C-C cross-coupling reactions.
- Ghasemzadeh, Maryam Sadat,Akhlaghinia, Batool
-
p. 674 - 692
(2019/07/12)
-
- Tetranuclear Palladium Complexes of Abnormal N-Heterocyclic Carbene Ligands and their Catalytic Activities in Mizoroki-Heck Coupling Reaction of Electron-Rich Aryl Chlorides
-
Based on the ligand scaffold of an imidazolyl/benziimidazolyl moiety and a N-CH2C(=O)NHPh substituent, two series of ligand precursors with ortho hydroxy groups incorporated on the N-phenyl rings were prepared. The structural fine tuning of the ligand scaffold allowed the synthesis of tetranuclear palladium complexes with abnormal N-heterocyclic carbene (aNHC) ligands. For precursors with C2-methyl blocking groups, pyridine-assisted C?H bond activation led to the formation of mononuclear tridentate palladium aNHC complexes or tetranuclear complexes with tridentate CNO donors. Representative mononuclear and tetranuclearpalladium aNHC complexes were structurally characterized by X-ray diffraction studies, revealing very short Pd?C bond distances. The tetranuclear palladium aNHC complexes were very effective in catalyzing Mizoroki-Heck coupling reaction, and were capable of employing a range of aryl chlorides including deactivated substrates with low palladium loading of 0.2 mol%. (Figure presented.).
- Lee, Jhen-Yi,Su, Yong-Siang,Wang, Yu-Shan,Lee, Hon Man
-
p. 4714 - 4726
(2019/09/03)
-
- Palladium(ii) ligated with a selenated (Se, CNHC, N-)-type pincer ligand: An efficient catalyst for Mizoroki-Heck and Suzuki-Miyaura coupling in water
-
A new 1-[N-benzylacetamido]-3-[1-(2-phenylselenylethyl)]benzimidazolium chloride (L), the precursor of a novel (Se, CNHC, N-)-type pincer ligand (L) was synthesised in high yield through a sequence of consecutive reactions of 1H-benzimidazole with ethylene dichloride, sodium selenophenolate, and N-benzyl-2-chloroacetamide. The palladium-promoted reaction of L with PdCl2 resulted in a moisture- and air-insensitive complex [Pd(L-H2Cl)Cl] (1), which demonstrated outstanding catalytic potential for Mizoroki-Heck coupling of aromatic bromides and chlorides (with yields up to 94% and 70%, respectively) at very low catalyst loading (0.2 mol%) and under mild reaction conditions in water. The complex (1) was also investigated for Suzuki-Miyaura coupling and found to be selectively efficient (yields up to 94%) for Suzuki-Miyaura coupling of aromatic bromides at 0.01 mol% of 1 in water. All coupling reactions were carried out in the green and economical solvent, water, which is highly desirable for bulk synthesis of complex molecules in industry. During the catalytic process, complex 1 converted into PdSe nanoparticles (NPs, size range 5-6 nm) in situ. The morphology and composition of these NPs were analysed through high-resolution transmission electron microscopy and transmission electron microscopy-energy dispersive X-ray spectroscopy, respectively. The core-level, X-ray photoelectron spectroscopy analysis confirmed the presence of stable Pd0 and Pd2+ oxidation states in these PdSe NPs. Based on further experimental investigations, these nanoparticles were found to work as a stock of true catalytic species. The hot filtration test, as well as the two-phase test, confirmed the largely homogeneous nature of the catalytic process, which probably proceeds by leaching of solution-phase Pd species from these NPs.
- Sharma, Kamal Nayan,Satrawala, Naveen,Srivastava, Avinash Kumar,Ali, Munsaf,Joshi, Raj Kumar
-
p. 8969 - 8976
(2019/10/28)
-
- N-HETEROCYCLIC CARBENE (NHC) BASED LIGANDS AND RELATED METHODS
-
Polydentate macrocyclic NHCs (NHC ligands) and related methods are disclosed. Such ligands advantageously facilitate a variety of ligand coordination modes and stabilize oxidation states of metal complexes with a number of coordination environments and shapes. The NHC ligands described herein comprise pendant groups configured to facilitate a variety of reactions including: cis-trans isomerization, proton shuttling and facilitating changes in coordination environments as a result of redox reactions.
- -
-
Paragraph 0042; 0043; 0045
(2019/03/02)
-
- Synthesis and structural characterization of 20-membered macrocyclic rings bearing: Trans -chelating bis(N-heterocyclic carbene) ligands and the catalytic activity of their palladium(ii) complexes
-
Macrocycles consisting of a 20-membered ring containing two imidazolium salt functionalities and of the formula [PhCH2N(CH2CH2CH2)Im(CH2CH2CH2)2][Br]2 (Im = imidazole = 3a, benzimidazole = 3b) were synthesized in 70-75% yields. These salts serve as precursors to macrocycles containing two N-heterocyclic carbene (NHC) moieties. Reaction of the macrocyclic salts 3a and 3b with silver oxide afforded macrocyclic-bis(NHC)silver(i) complexes 4a and 4b. Single-crystal X-ray diffraction studies of macrocyclic-bis(NHC)silver(i) complex 4a revealed a tetranuclear silver core with a short Ag-Ag distance (2.9328 ?). Complexes 4a and 4b serve as carbene transfer reagents to Pd. The treatment of macrocyclic-bis(NHC)silver(i) complexes 4a and 4b with one equivalent of PdCl2(MeCN)2 in methylene chloride afforded square-planar trans-macrocyclic-bis(NHC)Pd(ii)X2 complexes 5a and 5b. Preliminary screening of these palladium complexes showed they are competent precatalysts for Heck and Suzuki coupling reactions.
- Thapa, Rajesh,Kilyanek, Stefan M.
-
p. 12577 - 12590
(2019/08/26)
-
- Cellulose supported Pd(II) complex catalyzed carbon-carbon bonds formation
-
Corn-cobs are an agro-industrial waste and composed of cellulose mostly. In this study cellulose was isolated from the waste corn-cobs and modified to polymeric hydroxamic acid palladium complex 1 and characterized by using a variety of spectroscopic methods such as field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The complex 1 exhibited high catalytic activity towards Suzuki and Heck coupling reactions of activated and deactivated aryl halides to give the respective coupling products with high yield. Moreover, the complex 1 was recovered and recycled five times with no considerable loss of catalytic overall performance.
- Sarkar, Shaheen M.,Rashid,Karim, Kaykobad Md. Rezaul,Mustapha, Siti Noor Hidayah,Lian, Yuen Mei,Zamri, Normaiza,Khan, Md. Maksudur Rahman,O'Reilly, Emmet J.,Rahman, Md. Lutfor
-
p. 2856 - 2861
(2019/01/03)
-
- Bis-salophen palladium complex immobilized on Fe3O4@SiO2 nanoparticles as a highly active and durable phosphine-free catalyst for Heck and copper-free Sonogashira coupling reactions
-
New Fe3O4@SiO2 core-shell superparamagnetic nanoparticles functionalized by a bis-salophen Schiff base Pd complex were synthesized and employed as an efficient magnetic nanocatalyst in the Heck and Sonogashira cross coupling reactions. The synthesized nanostructures were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), dynamic light scattering (DLS), energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), elemental analysis (CHN), cyclic voltammetry (CV), Brunauer-Emmett-Teller analysis (BET), and UV-vis spectroscopy. The morphology and size of the nanoparticles were investigated by FE-SEM and TEM analyses. Furthermore, the magnetic properties of the catalyst were investigated by VSM analysis. The loading content and leaching amounts of palladium on the catalyst were measured by inductively coupled plasma (ICP) analysis. Also, the thermal behavior of this magnetic heterogeneous catalyst was studied using a TGA instrument. This heterogeneous catalytic system showed a good performance in the coupling of aryl halides with alkynes (Sonogashira reaction) as well as aryl halides with alkene derivatives (Heck reaction). High to excellent yields were achieved for these C-C coupling reactions. The catalyst can be simply separated from the reaction media by an external magnet and reused for eight consecutive runs without any significant loss of activity. Finally, the kinetics of the reactions were studied in this work.
- Sardarian, Ali Reza,Kazemnejadi, Milad,Esmaeilpour, Mohsen
-
p. 3132 - 3145
(2019/03/06)
-
- Green, cost-effective and efficient procedure for Heck and Sonogashira coupling reactions using palladium nanoparticles supported on functionalized Fe3O4@SiO2 by polyvinyl alcohol as a highly active, durable and reusable catalyst
-
A novel heterogenized organometallic catalyst was synthesized by coordinating palladium with polyvinyl alcohol-functionalized Fe3O4@SiO2 nanospheres. This novel catalyst was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscope, field emission scanning electron microscope, dynamic light scattering, UV–vis spectroscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray analysis, thermogravimetric analysis and inductively coupled plasma analysis. The prepared palladium nanoparticles supported on polyvinyl alcohol functionalized Fe3O4@SiO2 nanoparticles were successfully applied as a magnetically recyclable catalyst in Heck and Sonogashira coupling reactions in water. They showed remarkable activity toward aryl halides (I, Br, Cl) using very low palladium loading in excellent yields and demonstrated high TONs (mmol of product per mmol of catalyst). Also, the catalyst could be magnetically separated and reused seven times without any appreciable loss of catalytic activity.
- Sardarian, Ali Reza,Eslahi, Hassan,Esmaeilpour, Mohsen
-
-
- Palladium nanoparticles immobilized on EDTA-modified Fe3O4@SiO2: a highly stable and efficient magnetically recoverable catalyst for the Heck–Mizoroki coupling reactions
-
Palladium nanoparticles supported on EDTA-modified Fe3O4@SiO2 NPs as an efficient and magnetically reusable nanocatalyst was applied for the Heck cross-coupling reactions. The catalyst was very effective for the Heck reaction of aryl halides (iodides, bromides, and chlorides) with alkenes and conversion was excellent in most cases with higher TOF (turn over frequency). Moreover, the catalyst could be recycled for eight runs without any significant loss of catalytic activity, showing its superiority over homogeneous catalysts for industrial and chemical applications. Also, the leaching of the catalyst has been examined by a hot filtration test and ICP analysis.
- Esmaeilpour, Mohsen,Zahmatkesh, Saeed
-
p. 267 - 276
(2019/09/13)
-
- Imidazolium chloride-Co(iii) complex immobilized on Fe3O4@SiO2 as a highly active bifunctional nanocatalyst for the copper-, phosphine-, and base-free Heck and Sonogashira reactions
-
A heterogeneous, magnetically recoverable Fe3O4@SiO2@Im[Cl]Co(iii)-melamine nanocomposite was prepared by immobilization of a novel Co(iii) Schiff base complex on Fe3O4@SiO2 nanoparticles followed by treatment with melamine, and was found to be an efficient catalyst for the Heck and Sonogashira reactions. The reactions were performed in the presence of the catalyst (0.5 mol% Co) along with Mn additive in the absence of any base, phosphine ligand, or Cu/co-catalyst in ethanol under reflux conditions. The nanocatalyst was well studied by FTIR, CHN, XRD, XPS, TGA, EDX, VSM, ICP, NMR, FE-SEM, TEM, BET, CV, and DLS analyses. The catalyst was compatible with a variety of substrates, with which all the Heck and Sonogashira coupling products were obtained in high to excellent yields. Also, protocols such as hot filtration, three-phase testing, and mercury poisoning provided a complete insight into the nature of the heterogeneous catalyst. The recycling and reuse of the catalyst were studied for both coupling reactions several times. Moreover, the mechanism of the coupling reactions was entirely investigated.
- Kazemnejadi, Milad,Alavi, Seyyedeh Ameneh G.,Rezazadeh, Zinat,Nasseri, Mohammad Ali,Allahresani, Ali,Esmaeilpour, Mohsen
-
p. 1718 - 1734
(2019/04/08)
-
- Cobalt supported on dendronized magnetic nanoparticles: A new highly efficient and recyclable catalyst for the Mizoroki–Heck cross-coupling reaction
-
Polyamidoamine (PAMAM) is one of the most interesting types of hyperbranched polymers that carry a large number of amino groups on its surface. PAMAM has gained significant attention from synthetic organic chemists due to its structural characteristics, controllable structure, inner porosity, and ability to trap a wide range of ions and molecules. So, in this work, the PAMAM dendrimer was synthesized, grafted onto the surface of magnetite nanoparticles, and the resulting hybrid nanoparticles were then employed as suitable host for immobilizing cobalt nanoparticles. The newly developed catalyst was well characterized by Fourier transform-infrared, X-ray diffraction, thermogravimetric analysis, field emission-scanning electron microscopy, transmission electron microscopy, atomic absorption spectroscopy, element mapping and energy-dispersive X-ray analysis. The efficiency of the as-prepared nanocatalyst was evaluated for the Mizoroki–Heck cross-coupling reactions. The MNP@PAMAM-Co represented perfect catalytic efficiency and high selectivity for the Mizoroki–Heck cross-coupling reaction compared with previously reported catalysts. The catalyst separation from the reaction mixture was easily achieved with the assistance of an external magnetic field, and its recycling was also investigated for five consecutive runs. Hot filtration confirmed no leaching of the active metal during the Heck coupling.
- Arghan, Maryam,Koukabi, Nadiya,Kolvari, Eskandar
-
-
- Ionic Pd/NHC Catalytic System Enables Recoverable Homogeneous Catalysis: Mechanistic Study and Application in the Mizoroki–Heck Reaction
-
N-Heterocyclic carbene (NHC) ligands are ubiquitously utilized in catalysis. A common catalyst design model assumes strong M–NHC binding in this metal–ligand framework. In contrast to this common assumption, we demonstrate here that lability and controlled cleavage of the M?NHC bond (rather than its stabilization) could be more important for high-performance catalysis at low catalyst concentrations. The present study reveals a dynamic stabilization mechanism with labile metal–NHC binding and [PdX3]?[NHC-R]+ ion pair formation. Access to reactive anionic palladium intermediates formed by dissociation of the NHC ligands and plausible stabilization of the molecular catalyst in solution by interaction with the [NHC-R]+ azolium ion is of particular importance for an efficient and recyclable catalyst. These ionic Pd/NHC complexes allowed for the first time the recycling of the complex in a well-defined form with isolation at each cycle. Computational investigation of the reaction mechanism confirms a facile formation of NHC-free anionic Pd in polar media through either Ph–NHC coupling or reversible H–NHC coupling. The present study formulates novel ideas for M/NHC catalyst design.
- Eremin, Dmitry B.,Denisova, Ekaterina A.,Yu. Kostyukovich, Alexander,Martens, Jonathan,Berden, Giel,Oomens, Jos,Khrustalev, Victor N.,Chernyshev, Victor M.,Ananikov, Valentine P.
-
supporting information
(2019/11/14)
-
- Boehmite@tryptophan-Pd nanoparticles: A new catalyst for C–C bond formation
-
A boehmite@tryptophan-Pd nanoparticulate catalyst was prepared by a simple, fast and convenient route. The nanomaterial was characterized using various techniques and employed as a thermally stable catalyst for Heck, Stille and Suzuki cross-coupling reactions. Optimized conditions for these reactions are described. The catalyst could be isolated, post-reaction, by simple filtration and recycled for several consecutive cycles without a notable change in its activity.
- Ghorbani-Choghamarani, Arash,Mohammadi, Masoud,Hudson, Robert H.E.,Tamoradi, Taiebeh
-
-
- Synthesis and characterization of γ-Fe2O3@SiO2-(CH2)3-PDTC-Pd magnetic nanoparticles: A new and highly active catalyst for the Heck/Sonogashira coupling reactions
-
In this research, the synthesis and characterization of a novel catalyst is reported based on the preparation of the Pd complex of (pyridin-2-ylmethyl)dithiocarbamate (PDTC) supported on γ-Fe2O3@SiO2 magnetic nanoparticles (γ-Fe2O3@SiO2-(CH2)3-PDTC-Pd). The catalyst is characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, inductively coupled plasma analysis, X-ray powder diffraction, X-ray photoelectron spectroscopy, and vibrating-sample magnetometer measurements. The catalytic performance of γ-Fe2O3@SiO2-(CH2)3-PDTC-Pd was evaluated in the Heck/Sonogashira coupling reactions of various aryl halides with various alkenes/phenylacetylene in water. The synthesized nanocatalyst showed a high catalytic activity even in very small amounts (5 mg, less than 0.1 mol%), was easily separated using magnetic decantation and was reused for ten cycles without any appreciable loss of its reactivity.
- Tashrifi, Zahra,Bahadorikhalili, Saeed,Lijan, Hossein,Ansari, Samira,Hamedifar, Haleh,Mahdavi, Mohammad
-
p. 8930 - 8938
(2019/06/17)
-
- A Palladium NNC-Pincer Complex as an Efficient Catalyst Precursor for the Mizoroki?Heck Reaction
-
The Mizoroki?Heck reaction of aryl halides (iodides, bromides, or chlorides) with activated alkenes in the presence of a palladium NNC-pincer complex at ppb to ppm loadings gave the corresponding internal alkenes in excellent yields. The total turnover number and turnover frequency reached up to 8.70×108 and 1.21×107 h?1 (3.36×103 s?1), respectively. The catalyst was applied in a ten-gram-scale synthesis of the UV-B sunscreen agent octinoxate (2-ethylhexyl 4-methoxycinnamate). Reaction-rate analyses, transmission electron microscopic examination of the reaction mixture, and poisoning tests suggested that a monomeric palladium species is the catalytically active species in the catalytic cycle. (Figure presented.).
- Hamasaka, Go,Ichii, Shun,Uozumi, Yasuhiro
-
supporting information
p. 1833 - 1840
(2018/04/05)
-
- A practical method for heterogeneously-catalyzed Mizoroki–Heck reaction: Flow system with adjustment of microwave resonance as an energy source
-
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.
- Ichikawa, Tomohiro,Mizuno, Masahiro,Ueda, Shun,Ohneda, Noriyuki,Odajima, Hiromichi,Sawama, Yoshinari,Monguchi, Yasunari,Sajiki, Hironao
-
p. 1810 - 1816
(2018/03/07)
-
- Synthesis and Characterization of C, C -Type Palladacycles and Their Catalytic Application in Mizoroki-Heck Coupling Reaction
-
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.
- Lo, Chi Hou,Lee, Hon Man
-
p. 1150 - 1159
(2018/04/17)
-
- Catalytic Performance Studies of New Pd and Pt Schiff Base Complexes Covalently Immobilized on Magnetite Nanoparticles as the Environmentally Friendly and Magnetically Recoverable Nanocatalyst in C–C Cross Coupling Reactions
-
Abstract: Synthesis and characterization of new magnetically recoverable and high-performance nanocatalysts of Pd and Pt Schiff base complexes on magnetite nanoparticles were considered. Catalytic activity of these nanocatalysts was explored in Suzuki and Heck cross coupling reactions. The catalysts can be easily reused fourth consecutive runs without significant loss of catalytic efficiency.
- Rezaei,Naghipour,Fakhri
-
p. 732 - 744
(2017/12/26)
-
- Organometallic polymer-functionalized Fe3O4 nanoparticles as a highly efficient and eco-friendly nanocatalyst for C–C bond formation
-
A magnetically recoverable biopolymer-based nanocatalyst was prepared through the covalent immobilization of a chitosan-bound 2-hydroxynaphthaldehyde Pd complex on the surface of superparamagnetic nanoparticles. The nanocatalyst was characterized by FTIR, X-ray powder diffraction and scanning electron microscopy, revealing an average particle size of 70?nm. The catalyst shows high thermostability by thermogravimetric analysis. Estimated Pd loading by inductively coupled plasma atomic emission analysis was found to be 0.348?mmol?g?1. The nanocatalyst exhibits excellent catalytic performance in Suzuki couplings of various aryl halides with phenylboronic acid, and Heck reactions of iodo- and bromoarenes with butylacrylate. The catalyst can be easily separated from the reaction mixture with an external magnet and reused consecutively four times without significant loss in activity.
- Fakhri, Akram,Naghipour, Ali
-
p. 463 - 472
(2018/04/17)
-
- Thermo-responsive poly(N -isopropylacrylamide)- block -poly(ionic liquid) of pyridinium sulfonate immobilized Pd nanoparticles in C-C coupling reactions
-
A thermo-responsive poly(N-isopropylacrylamide)-block-poly(ionic liquid) (PNIPAM-b-PIL) of pyridinium-type was prepared. Initially, controlled synthesis of PNIPAM was performed via RAFT method. Subsequently, PNIPAM as macromolecular chain transfer agent (macro-CTA) was used for fabrication of PNIPAM-b-PIL through reaction with a synthesized IL monomer i.e. 4-vinyl pyridinium propane sulfonate. The Pd catalyst was produced throughout palladium nanoparticles' anchoring into this block copolymer. The catalyst was characterized using ICP, FT-IR, NMR, UV-Vis, TGA, XRD, SEM and EDX techniques. The catalyst's TEM image proved nearly fine dispersion of PdNPs with negligible agglomeration. The catalyst was used in the production of a variety of substituted alkenes and biaryl compounds (Heck and Suzuki coupling) in organic and aqueous media and under solvent free conditions. Additionally, the results signified extreme reusability of the catalyst with a simple recycling procedure.
- Ghasemi, Soheila,Harandi, Zahra Amini
-
p. 14570 - 14578
(2018/04/26)
-
- Iron-catalyzed cross-coupling reaction: Heterogeneous palladium and copper-free Heck and Sonogashira cross-coupling reactions catalyzed by a reusable Fe(III) complex
-
An interesting silica-supported iron catalyst was successfully prepared and demonstrated as an efficient heterogeneous catalyst for cross-coupling reactions of aryl halides. The as-prepared nanocatalyst was well characterized and found to be highly efficient in Heck reaction under mild and sustainable conditions (water as solvent at 80?°C in short reaction time). Furthermore, the obtained catalyst was used as an efficient, inexpensive and green heterogeneous catalyst for Sonogashira cross-coupling reactions of various aryl iodides and provided the corresponding products with moderate to good yields. This phosphine, copper and palladium-free catalyst was simply recovered from the reaction mixture and recycled five times without substantial decrease in its catalytic activity.
- Hajipour, Abdol R.,Abolfathi, Parisa,Tavangar-Rizi, Zeinab
-
-
- Anchored complexes of Ni, Pt, and Pd on Fe3O4 nanoparticles as new and eco-friendly nanocatalysts in Suzuki and Heck coupling reactions
-
Three recoverable nanocatalysts were developed by immobilizing Ni, Pt, and Pd Schiff-base complexes on the magnetite nanoparticles. Successful preparation of the nanocatalysts was evidenced by Fourier transform infrared (FT-IR) and energy dispersive X-ray (EDX) spectroscopy. Nano-sized spherical structure of the nanocatalysts was indicated by scanning electron microscopy (SEM). X-ray powder diffraction (XRD) determined that the crystalline cubic spinel structure of Fe3O4 remained constant through the synthesis of three complexes on Fe3O4 nanoparticles. Magnetic properties of the nanocatalysts were analyzed by the vibration sample magnetometer (VSM). Thermostability of the nanocatalysts was studied by thermogravimetric analysis (TGA). Metal loading of these nanocatalysts was evidenced by inductively coupled plasma atomic emission (ICP-AES). Investigating the catalytic activity of these nanocatalysts in Suzuki and Heck reactions implicated that in the presence of Pd nanocatalyst coupling reactions proceeded efficiently. For Pt nanocatalyst, Suzuki reaction took place in longer time with moderate to good yield. For the Heck reaction, the desired products were achieved only for aryl iodide and some aryl bromides. The Ni nanocatalyst could just catalyze the Suzuki reaction. Relying on the magnetic characteristic, these nanocatalysts could be simply recovered and reused several cycles without significant loss in catalytic activity.
- Rezaie, Gisa,Naghipour, Ali,Fakhri, Akram
-
p. 2924 - 2940
(2018/09/21)
-
- Pd(0)- S-propyl-2-aminobenzothioate immobilized onto functionalized magnetic nanoporous MCM-41 as efficient and recyclable nanocatalyst for the Suzuki, Stille and Heck cross coupling reactions
-
The present work describes the use of Pd(0)- S-propyl-2-aminobenzothioate Complex immobilized onto functionalized magnetic nanoporous MCM-41(Fe3O4@MCM-41@Pd-SPATB) as efficient and recyclable nano-organometallic catalyst for C–C bond formation between various aryl halides with phenylboronic acid (Suzuki reaction), aryl halides with triphenyltin chloride (Stille reaction), and aryl halides with n-butyl acrylate (Heck reaction). All the reactions were carried out in PEG-400 as green solvent with short reaction time and good to excellent yields. This catalyst was characterized by FT-IR spectroscopy, XRD, TGA, VSM, ICP-OES, TEM, EDX and SEM techniques. Ease of operation, high efficiency, recovery and reusability for five continuous cycles without significant loss of its catalytic activities or metal leaching are the noteworthy features of the currently employed heterogeneous catalytic system.
- Nikoorazm, Mohsen,Ghorbani, Farshid,Ghorbani-Choghamarani, Arash,Erfani, Zahra
-
-
- Fe3O4@Boehmite-NH2-CoII NPs: An inexpensive and highly efficient heterogeneous magnetic nanocatalyst for the Suzuki-Miyaura and Heck-Mizoroki cross-coupling reactions
-
Herein we report the synthesis of a magnetically separable core-shell-like Fe3O4@Boehmite-NH2-CoII NPs as an environmentally friendly heterogeneous catalyst. The as-prepared nanocatalyst was well characterized by various techniques such as FT-IR, XRD, BET, TEM, FE-SEM, EDX, TGA, H2-TPR, VSM, ICP-OES and elemental analysis and evaluated for the Suzuki-Miyaura and Heck-Mizoroki cross-coupling reactions in a green solvent (H2O). The results of characterization studies revealed the superparamagnetic behavior of the Fe3O4 NP core encapsulated by a Boehmite NP shell. Also, it was clearly found that the size of the particles was about 13-54 nm. In comparison with previously reported catalysts, Fe3O4@Boehmite-NH2-CoII NPs exhibited perfect catalytic efficiency for the Suzuki-Miyaura and Heck-Mizoroki cross-coupling reactions under mild conditions without using toxic solvents. The concerted effects between individual components of the catalyst and also its unique egg-like nanostructure led to the high catalytic performance of Fe3O4@Boehmite-NH2-CoII NPs. Also, the introduction of Co significantly lowers the cost of the catalyst. More importantly, the longevity of the nanocatalyst was studied and it was found that the magnetic nanocatalyst was stable under the reaction conditions and could be easily reused for at least seven consecutive cycles without a discernible decrease in its catalytic activity or metal leaching.
- Mohammadinezhad, Arezou,Akhlaghinia, Batool
-
p. 5625 - 5641
(2017/12/06)
-
- Silica-coated nano-Fe3O4-supported iminopyridine palladium complex as an active, phosphine-free and magnetically separable catalyst for Heck reactions
-
A novel magnetic nanoparticle-supported iminopyridine palladium complex was successfully prepared by attaching palladium acetate to iminopyridine ligand-functionalized silica-coated nano-Fe3O4. The as-prepared catalyst was well characterized and was evaluated in Heck reactions in terms of activity and recyclability. It was found to be highly efficient for the reactions of various aryl iodides and aryl bromides having electron-withdrawing groups with olefins under phosphine-free and inert atmosphere-free conditions. Moreover, the catalyst could be conveniently recovered using an external magnet, and the recyclability was influenced by the base in the Heck reaction. The catalyst could be reused at least six times with no significant loss in activity when triethylamine acted as the base.
- Zhang, Qiang,Zhao, Xin,Wei, Huai-Xin,Li, Ji-Hang,Luo, Jun
-
-
- Chitosan microspheres-supported palladium species as an efficient and recyclable catalyst for Mizoroki-Heck reaction
-
Chitosan microspheres-supported palladium catalysts (Pd@CM) for Mizoroki-Heck reaction have been successfully prepared by electrospraying PdCl2/chitosan mixture in a trifluoroacetic acid (TFA) aqueous solution. Swelling capacity measurement and thermal analysis demonstrated that the palladium species in the chitosan microspheres could cross-link the chitosan efficiently. FT-IR spectra demonstrated that the chitosan in the microspheres could be cross-linked by glutaraldehyde, and the formed Schiff bond could chelate the palladium species efficiently. High resolution transmission electron microscopy (HR-TEM) indicated that the entrapment of palladium species in chitosan microspheres could enhance its dispersion. Mizoroki-Heck reaction catalysis results demonstrated that the catalytic activity of Pd@CM was associated with the size of chitosan microspheres. The Pd@CM with a suitable size was even more active than the catalyst with palladium species adsorbed on the surface of chitosan microspheres (Pd-CM). Moreover, the entrapment of palladium species in chitosan microspheres could reduce its aggregation and leaching in the catalysis procedure, which in turn increased the reusability of Pd@CM catalyst. The high catalytic activity and stability of Pd@CM have been attributed to the entrapment of palladium species within the cross-linked chitosan microspheres and the chelation of palladium species with the abundant amine and hydroxyl groups on chitosan chain.
- Shao, Linjun,Qi, Chenze
-
p. 8156 - 8165
(2017/08/15)
-
- An efficient palladium catalyzed Mizoroki-Heck cross-coupling in water
-
The homogeneous Pd-catalysed Mizoroki-Heck coupling reaction was successfully performed in water in the absence of any additives under aerobic conditions. The various key reaction parameters that affect the yield of the desired cross-coupling product were optimized. The Pd(PPh3)4/Et3N/H2O/98 °C catalyst system was found to be highly active (TOF = 12 to 14 h-1) towards achieving excellent yield of the Mizoroki-Heck coupling products for a wide range of electron-withdrawing as well as electron-donating aryl bromides and chlorides in the shortest reaction time. Pd(PPh3)4 catalyst deactivation during the Mizoroki-Heck coupling reaction was investigated and to evolve a strategy for achieving ten times Pd-metal recyclability without appreciable loss of its activity. Thus, the proposed mechanism provides access to a variety of olefins in aqueous medium, making this protocol eco-friendly.
- Jadhav, Sanjay N.,Rode, Chandrashekhar V.
-
supporting information
p. 5958 - 5970
(2017/12/26)
-
- Macrocyclic Pd(II) dithiolate complexes as catalysts in Heck reactions
-
The supramolecular palladium dithiolate complexes, [Pd2(dppe)2{S(C6H4)nS}]2(OTf)4and [Pd2(dppe)2(SCH2C6H4CH2S)]
- Mane, Pravin A.,Dey, Sandip,Vivekananda
-
supporting information
p. 25 - 29
(2016/12/23)
-
- A palladium complex immobilized onto mesoporous silica: a highly efficient and reusable catalytic system for carbon–carbon bond formation and anilines synthesis
-
A palladium complex supported on functionalized mesoporous silica MCM-41 proved to be a highly efficient, recoverable catalyst for C–C coupling reactions and amination of aryl halides to afford anilines. The nanocatalyst was characterized by FT-IR spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, N2 adsorption–desorption isotherms and inductively coupled plasma analysis. The catalyst could be reused for several consecutive runs without significant loss of activity. The excellent yields of products, simple reaction procedures and short reaction times are the main advantages of this methodology.
- Nikoorazm, Mohsen,Noori, Nourolah,Tahmasbi, Bahman,Faryadi, Sara
-
p. 469 - 481
(2017/07/12)
-
- Magnetically water-dispersible and recoverable rhodium organometallic catalyst derived from Wilkinson's catalyst for promoting organic reactions
-
A novel magnetic rhodium catalyst was prepared through immobilizing Wilkinson's catalyst on the surface of silica-coated iron oxide nanoparticles. After (thio)diphenylphosphine (─S─PPh2) was modified on the surface of the silica-coated iron oxide nanoparticles, tris(triphenylphosphine)rhodium(I) chloride was employed to synthesize the Rh(Cl)(PPh3)2(Ph2P─S─) complex, affording a rhodium loading of 0.16?mmol?g?1. The Rh(I) organometallic magnetic nanoparticles form a novel class of heterogeneous catalyst which is particularly suitable for the practice of organic synthesis. The prepared system exhibits high catalytic efficiency in Suzuki–Miyaura and Miyaura–Michael reactions in ethanol–water solution. High yield, low reaction times, use of green solvents and non-toxicity of the catalyst are the main merits of this protocol. Also, magnetic separation is an environmentally friendly alternative for the recovery of the catalyst, since it minimizes energy and catalyst loss by preventing mass loss and oxidation. The produced catalyst was characterized using a variety of techniques.
- Nejat, Razieh,Mahjoub, Alireza
-
-