- Palladium(II) complexes bearing methylene and ethylene bridged pyrido-annelated N-heterocyclic carbene ligands as active catalysts for Heck and Suzuki-Miyaura cross-coupling reactions
-
The synthesis and characterization of new bidentate N-heterocyclic carbene ligands is described. The ligands are derived from methylene (me) and ethylene (et) bridged imidazo[1,5-a]pyridine-3-ylidenes (impy) and can be synthesized readily from imidazo[1,5-a]pyridine and the respective dihaloalkanes. Palladium(II) dihalide complexes bearing these et(impy)2 or me(impy)2 ligands were prepared and also structurally characterized. The angle of the impy plane vs. the C-Pd-C plane is depending on the bridging unit as well as the halide ligands. In the solid state the me(impy)2PdBr2 complex forms a dimer by weak intermolecular Pd-hydrogen bridges. The activity of the Pd-complexes as catalysts for the Heck and Suzuki-Miyaura reactions was tested under various conditions. The catalysts show good activity at 120 °C in Heck and at 85 °C in Suzuki-Miyaura reactions.
- Nonnenmacher, Michael,Kunz, Doris,Rominger, Frank,Oeser, Thomas
-
-
Read Online
- Recycling Pd colloidal catalysts using polymeric phosphine ligands and polyethylene as a solvent
-
Polyisobutylene (PIB)-bound azo dyes were prepared from aryl amine terminated polyisobutylene oligomers and used to form palladacycle precatalysts that can be used for catalytic carbon-carbon cross coupling reactions. The catalysts so formed were recyclable using thermomorphic heptane-DMF solutions that are monophasic at 80 °C and biphasic at room temperature. Under these conditions, the Pd catalyst can be recycled but some Pd leaches into the product solution. Using a low melting polyethylene oligomer as a solvent in place of the volatile heptane solvent reduces this leaching by roughly an order of magnitude. Further modification that involves using a second polyisobutylene (PIB)-bound phosphine ligand both increases the activity of the colloidal Pd catalyst and decreases the total Pd leaching by almost two orders of magnitude with 99.88% of the Pd being recovered. In this case, the Pd content in the solution of the product was ca. 0.3 ppm. These two modifications together lead to a much more sustainable strategy for the use of Pd colloidal catalysts in catalytic cross coupling chemistry.
- Priyadarshani, Nilusha,Suriboot, Jakkrit,Bergbreiter, David E.
-
-
Read Online
- Strong evidence of solution-phase catalysis associated with palladium leaching from immobilized thiols during Heck and Suzuki coupling of aryl iodides, bromides, and chlorides
-
A 3-mercaptopropyl-functionalized silica, SH-SBA-15, is used both as a support for palladium acetate, Pd-SH-SBA-15, and as a selective poison of soluble palladium complexes. Pd-SH-SBA-15 is used as a precatalyst for Heck and Suzuki couplings of an aryl io
- Richardson, John M.,Jones, Christopher W.
-
-
Read Online
- Investigating PdEnCat catalysis
-
The catalytic behavior of three commercially available PdEnCat catalysts was explored. When the three-phase test was used, it was demonstrated that these microencapsulated palladium catalysts act as heterogeneous sources, or reservoirs, for soluble, catalytically active species. In addition, kinetic data coupled with transmission electron microscopy and solvent-dependent investigations were used to support this conclusion.
- Broadwater, Steven J.,McQuade, D. Tyler
-
-
Read Online
- Pd-zeolites as heterogeneous catalysts in Heck chemistry
-
Heck reactions were performed with 4-bromoacetophenone and n-butyl acrylate, yielding the trans-arylated acrylate ester with high selectivity. Pd-zeolite catalysts were compared with supported Pd metal catalysts. In order to obtain an active and heterogen
- Dams,Drijkoningen,Pauwels,Van Tendeloo,De Vos,Jacobs, Pierre A.
-
-
Read Online
- Recyclable hybrid silica-based catalysts derived from Pd-NHC complexes for suzuki, heck and sonogashira reactions
-
Two silylated Pd-NHC complexes were immobilized on hybrid silicas by sol-gel cocondensation with tetraethyl orthosilicate (TEOS) and performed well as recyclable catalysts towards the Heck, Suzuki, and Sonogashira coupling reactions. Remarkable conversion
- Borja, Guadalupe,Monge-Marcet, Amalia,Pleixats, Roser,Parella, Teodor,Cattoen, Xavier,Wong Chi Man, Michel
-
-
Read Online
- Impact of Pd-mordenite pretreatment on the heterogeneity of Heck catalysis
-
In Heck reactions with tributylamine as the base and in toluene, Pd(NH3)42+-mordenite (0.4 wt% Pd) and Pd0-mordenite (0.4 and 4 wt% Pd) are not only active and selective, but also truly heterogeneous catalysts,
- Dams,Drijkoningen,De Vos,Jacobs, Pierre
-
-
Read Online
- Polyethylene as a nonvolatile solid cosolvent phase for catalyst separation and recovery
-
The studies described here show that a relatively low molecular weight, narrow polydispersity polyethylene (PE) wax (Polywax) can serve as a nontoxic and nonvolatile alternative to alkane solvents in monophasic catalytic organic reactions where catalysts
- Yang, Yanfei,Priyadarshani, Nilusha,Khamatnurova, Tatyana,Suriboot, Jakkrit,Bergbreiter, David E.
-
p. 14714 - 14717,4
(2012)
-
Read Online
- 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
-
-
- 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
-
-
- 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)
-
- Olefin Metathesis, p-Cresol, and the Second Generation Grubbs Catalyst: Fitting the Pieces
-
p-Cresol as additive to the Grubbs second generation catalyst (GII) allows the cross-metathesis of acrylates with prop-1-en-1-ylbenzenes under conditions that only give the prop-1-en-1-ylbenzene self-metathesis product in the absence of cresol. NMR and IR spectroscopy, MALDI-TOF MS and XPS supported the formation of a ruthenium benzylidene with hydrogen bonds between p-cresol and the chloride ligands of GII. XPS furthermore confirmed p-cresol to increase the binding energies of the GII Ru 3d5/2, 3d3/2, 3p3/2 and 3p1/2 photoelectron lines, whereas 1H NMR spectroscopy indicated the carbene carbon and hydrogen to be shielded. It is thus postulated that p-cresol allows for more facile interaction between electron-deficient compounds and the ruthenium benzylidene by decreasing the electron density on the metal center and increasing the electron density on the carbene.
- Swart, Marthinus R.,Twigge, Linette,Erasmus, Elizabeth,Marais, Charlene,Bezuidenhoudt, Barend C. B.
-
supporting information
p. 1752 - 1762
(2021/05/06)
-
- One-pot chemoenzymatic reactions in water enabled by micellar encapsulation
-
The use of micellar conditions to enable one-pot reactions involving both transition metal and enzymatic catalysts is reported. Representative enzymatic transformations under micellar conditions are unaffected by the presence of non-ionic surfactants, including designer surfactants such as TPGS-750-M. Furthermore, the presence of enzymes has a negligible effect on transition metal catalysis under micellar conditions in water. Finally, three one-pot chemoenzymatic reactions in water are reported in which the micelle-forming surfactant TPGS-750-M is a crucial factor for reaction efficiency.
- Adams, Nicholas P.,Bushi, Jurgen,Hastings, Courtney J.,Kolb, Samuel J.
-
supporting information
p. 6187 - 6193
(2020/10/18)
-
- 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)
-
- Base-Controlled Heck, Suzuki, and Sonogashira Reactions Catalyzed by Ligand-Free Platinum or Palladium Single Atom and Sub-Nanometer Clusters
-
The assumption that oxidative addition is the key step during the cross-coupling reaction of aryl halides has led to the development of a plethora of increasingly complex metal catalysts, thereby obviating in many cases the exact influence of the base, which is a simple, inexpensive, and necessary reagent for this paramount transformation. Here, a combined experimental and computational study shows that the oxidative addition is not the single kinetically relevant step in different cross-coupling reactions catalyzed by sub-nanometer Pt or Pd species, since the reactivity control is shifted toward subtle changes in the base. The exposed metal atoms in the cluster cooperate to enable an extremely easy oxidative addition of the aryl halide, even chlorides, and allow the base to bifurcate the coupling. With sub-nanometer Pd species, amines drive to the Heck reaction, carbonate drives to the Sonogahira reaction, and phosphate drives to the Suzuki reaction, while for Pt clusters and single atoms, good conversion is only achieved using acetate as a base. This base-controlled orthogonal reactivity with ligand-free catalysts opens new avenues in the design of cross-coupling reactions in organic synthesis.
- Fernández, Estefanía,Rivero-Crespo, Miguel A.,Domínguez, Irene,Rubio-Marqués, Paula,Oliver-Meseguer, Judit,Liu, Lichen,Cabrero-Antonino, María,Gavara, Rafael,Hernández-Garrido, Juan C.,Boronat, Mercedes,Leyva-Pérez, Antonio,Corma, Avelino
-
supporting information
p. 1928 - 1940
(2019/02/14)
-
- Facile synthesis of a recyclable Pd-rGO/CNT/CaFe2O4 nanocomposite with high multifunctional photocatalytic activity under visible light irradiation
-
We report a facile method to synthesize a magnetically separable Pd-rGO/CNT/CaFe2O4 photocatalyst. The incorporation of CNTs into rGO can form a conductive network structure to bridge the gaps between rGO sheets. This conductive netw
- Bagherzadeh, Mojtaba,Kaveh, Reyhaneh,Mahmoudi, Hamed
-
p. 16257 - 16266
(2019/07/16)
-
- A tailored polymeric cationic tag-anionic Pd(ii) complex as a catalyst for the low-leaching Heck-Mizoroki coupling in flow and in biomass-derived GVL
-
The [PdCl4]2- palladium complex has been immobilized on a polystyrene-type resin loaded with pincer-type imidazolium ionic tag binding sites. The catalytic system (Pd(ii)-POLI-TAG) has proved to be highly active in the definition of an efficient protocol for the Heck-Mizoroki coupling reaction under batch and flow conditions. Importantly, it is shown to be highly robust in combination with a safe non-toxic reaction medium, i.e. biomass-derived GVL, since it could be reused for multiple runs without significantly losing its activity.
- Mahmoudi, Hamed,Valentini, Federica,Ferlin, Francesco,Bivona, Lucia Anna,Anastasiou, Ioannis,Fusaro, Luca,Aprile, Carmela,Marrocchi, Assunta,Vaccaro, Luigi
-
supporting information
p. 355 - 360
(2019/01/28)
-
- Palladium-catalyzed Mizoroki-Heck reactions in water using thermoresponsive polymer micelles
-
Palladium-catalyzed Mizoroki-Heck reactions were carried out in water using thermoresponsive polymer micelles. The micelles were generated from thermoresponsive block copolymers consisting of a poly(N-isopropylacrylamide) (PNIPAAm) segment and a hydrophilic segment such as nonionic poly(ethylene glycol) (PEG) (2) and anionic poly(sodium p-styrenesulfonate) (PSSNa) (9). These copolymers exhibited lower critical solution temperature (LCST) behavior at ca. 40–50 °C and showed thermal stimuli-induced formation and dissociation of micelles. The copolymers formed micelles in aqueous solution at higher temperature, where catalytic reactions proceeded. At lower temperature, the micelles dissociated to form a clear solution, enabling efficient extraction of the products from aqueous reaction mixture. In the presence of these copolymers, palladium complexes catalyzed the coupling reactions between aryl iodides and alkene compounds inside the hydrophobic micelle cores in water under relatively milder conditions. Extraction of the products from the aqueous solution of 2 or 9 was found to be efficient enough in comparison with conventional surfactants.
- Suzuki, Noriyuki,Takabe, Taiga,Yamauchi, Yoshiko,Koyama, Shun,Koike, Rina,Rikukawa, Masahiro,Liao, Wei-Ting,Peng, Wen-Sheng,Tsai, Fu-Yu
-
p. 1351 - 1358
(2019/02/06)
-
- NHC stabilized Pd nanoclusters in the Mizoroki-Heck reaction within microemulsion: exploring the role of imidazolium salt in rate enhancement
-
We report the significant rate enhancement of the Mizoroki-Heck reaction by in situ generated palladium nanoclusters within the confined space of water-in-oil (w/o) mixed microemulsion (μE) formulated by sodium dodecylsulfate (SDS), polyoxyethylene (23) l
- Ghosh, Koena,Dhara, Shubhajit,Jana, Sourav,Das, Subhomoy,Roy, Sudeshna
-
p. 1993 - 2001
(2019/01/28)
-
- 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)
-
- 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)
-
- A polymer-supported salen-palladium complex as a heterogeneous catalyst for the Mizoroki-Heck cross-coupling reaction
-
In this work, the catalytic performance of a polymer-supported Pd(II)-salen complex (PS-Pd-salen) as an effective and environmentally friendly catalyst for the Mizoroki-Heck C[sbnd]C cross-coupling reaction is presented. The PS-Pd-salen complex was employed as a catalyst for Mizoroki-Heck reactions of an aryl halide with various terminal alkenes (Styrene, Methyl acrylate, Ethyl acrylate, n-butyl acrylate, tert-Butyl acrylate) under phosphine free conditions. Moreover, a range of Mizoroki-Heck reactions using different polar solvents, co-solvents, and bases has been investigated. Aryl iodides and bromides with terminal alkene are well activated in C[sbnd]C coupling reactions. All products were isolated by column chromatography as liquids/white to off-white crystalline solids and confirmed by 1H and 13C NMR spectroscopy. The catalyst could be easily separated by filtrations and reusability of catalyst was also assessed under optimized conditions. The hot filtration test revealed that the catalyst was truly heterogeneous, very active and stable under the reaction conditions and could be reused up to fifth cycles with analogous activities to that of the fresh catalyst. High catalytic activity at a low concentration (30 mg) and flexibility under mild reaction conditions, simple product work-up towards Mizoroki-Heck reactions indicated that PS-Pd-salen was an efficient catalyst for C[sbnd]C coupling reactions.
- Balinge, Kamlesh Rudreshwar,Bhagat, Pundlik Rambhau
-
-
- 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)
-
- Mizoroki–Heck Cross-Coupling of Acrylate Derivatives with Aryl Halides Catalyzed by Palladate Pre-Catalysts
-
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%).
- 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)
-
- Pd–Schiff base complex supported on Fe3O4 magnetic nanoparticles: A new and highly efficient reusable catalyst for C–C bond formation in water
-
A protocol is introduced for the preparation of a new cage-like Pd–Schiff base organometallic complex supported on Fe3O4 nanoparticles (Fe3O4@Schiff-base-Pd). The structure of the nanomagnetic catalyst was comprehensively characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller measurements, scanning electron microscopy (SEM), transmission electron microscopy, X-ray mapping, thermogravimetric analysis, vibrating sample magnetometry and inductively coupled plasma atomic emission spectroscopy. In the second stage, the catalytic activity of this catalyst was studied in the Suzuki and Heck cross-coupling reactions in water as a green solvent. In this sense, simple preparation of the catalyst from commercially available materials, high catalytic activity, simple operation, short reaction times, high yields and use of green solvent are some advantages of this protocol. Finally, the nanocatalyst was easily recovered, using an external magnet, and reused several times without significant loss of its catalytic efficiency. In addition, the stability of the catalyst after recycling was confirmed using SEM, XRD and FT-IR techniques.
- Lei, Lei
-
-
- Mizoroki–Heck cross-coupling reactions using palladium immobilized on DABCO-functionalized silica
-
A heterogeneous palladium catalyst supported on silica modified by DABCO has been prepared by post-synthetic modification of silica gel. This heterogeneous catalytic system exhibits high activity and stability in the Mizoroki–Heck cross-coupling reaction of various aryl halides with olefins. The reaction proceeds efficiently under efficiently under mild mild reaction conditions and high yield, with the formation of E-isomers selectively. Moreover, we successfully established a gram-scale synthesis, and the catalyst was reused for up to ten catalytic cycles.
- Jadhav, Sanjay,Patil, Seema,Kumbhar, Arjun,Kamble, Santosh,Salunkhe, Rajashri
-
p. 507 - 514
(2019/04/25)
-
- 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)
-
- 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)
-
- Synthesis of a novel ZnO nanoplates supported hydrazone-based palladacycle as an effective and recyclable heterogeneous catalyst for the Mizoroki-Heck cross-coupling reaction
-
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.
- Nouri, Fatemeh,Rostamizadeh, Shahnaz,Azad, Mohammad
-
p. 664 - 673
(2017/12/15)
-
- 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
-
supporting information
p. 1810 - 1816
(2018/03/07)
-
- Poly (methyl methacrylate)-graphene oxide supported palladium catalyst: A ligand free protocol for Suzuki and Heck coupling reaction in water medium
-
A green and efficient approach for the ligand free Suzuki–Miyaura and Mizoroki–Heck C–C cross coupling reaction using low palladium loaded Graphene oxide-polymer composite catalyst has been described. High yields, easy work-up, easy availability and handling, eco-friendly and reusability of the catalysts are the main aspects of the present method. The simplicity of the entire sequence has made the protocol meritorious as a reasonable contribution to the existing methods in the field of substituted biphenyls and olefins. The supported heterogeneous catalyst was characterized using HRTEM, ICP-AES, PXRD, XPS, TGA, and FT-IR spectroscopy.
- Basak, Puja,Ghosh, Pranab
-
supporting information
p. 2584 - 2599
(2018/10/20)
-
- Organosilane-Patterned Paper-based Colorimetric Sensors for High-Throughput Screening of Cross-Coupling Reactions with Aryl Bromides
-
An organosilane-patterned paper-based colorimetric sensor for bromides was developed using the 4-(2-pyridylazo)resorcinol (PAR)-Hg2+ complex and patterned hydrophobic paper. The red color of the (PAR)-Hg2+ spot was converted to yellow by ligand exchange between PAR and added bromide ions. This paper-based sensor was applied to detect the extent of conversion of aryl bromides in palladium-catalyzed coupling reactions such as Stille, Suzuki, Heck, direct arylation and decarboxylative coupling. A good correlation was demonstrated between the conversion of paper-based sensor and conversion of gas chromatography. (Figure presented.).
- Son, Yujeong,Lee, Suji,Kim, Han-Sung,Eom, Min Sik,Han, Min Su,Lee, Sunwoo
-
supporting information
p. 3916 - 3923
(2018/10/24)
-
- Palladium Stabilized by Amino-Vinyl Silica Functionalized Magnetic Carbon Nanotube: Application in Suzuki–Miyaura and Heck–Mizoroki Coupling Reactions
-
Abstract: This study describes an investigation on Suzuki and Heck cross-couplings of aryl electrophiles in the presence of heterogeneous Pd nanoparticles supported on amino-vinyl silica functionalized magnetic carbon nanotube. The core–shell contains CNT@Fe3O4@SiO2-Pd in which the functionalized SiO2 helps the stabilization of Pd nanoparticles and also responsible for the reduction of Pd(II) to Pd(0) without the need for adding external reducing agents. All of the reactions were done under phosphine-free condition. Graphical Abstract: [Figure not available: see fulltext.]
- Khalili, Dariush,Banazadeh, Ali Reza,Etemadi-Davan, Elham
-
p. 2674 - 2687
(2017/09/06)
-
- 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)
-
- Palladium-Alumoxane Framework as a Novel and Reusable Nanocatalyst for Suzuki–Miyaura, Stille and Heck Cross Coupling Reactions
-
Abstract: Herein for the first time, a Schiff base alumoxane-supported palladium (SBA-Pd°) were successfully synthesized and reported as a new mesoporous nanocatalyst for C–C cross coupling reactions. The SBA-Pd° nanocatalyst could be dispersed in poly(ethylene glycol) and showed excellent catalytic activity for Suzuki–Miyaura, Stille and Heck coupling reactions. In addition, the nanocatalyst could be recovered and reused several times without significant loss of its catalytic activity. Pd leaching from SBA-Pd° is very negligible for this coupling reaction. Graphical Abstract: [Figure not available: see fulltext.]
- Ghorbani-Choghamarani, Arash,Derakhshan, Ali Ashraf,Hajjami, Maryam,Rajabi, Laleh
-
p. 110 - 127
(2017/02/10)
-
- 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
-
-
- Nickel nanoparticles supported on diphenylphosphinated poly(vinyl alcohol-co-ethylene) as a new heterogeneous and recyclable catalyst for Mizoroki–Heck reactions
-
Nickel nanoparticles (NiNPs) supported on diphenylphosphinated poly(vinyl alcohol-co-ethylene) (DPP-PVA-co-PE) were synthesised by first reacting poly(vinyl alcohol-co-ethylene) with chlorodiphenylphosphine (ClPPh2) under basic conditions and then treating the product with Ni(OAc)2 followed by reduction with NaBH4. (DPP-PVA-co-PE)-NiNPs, a new metallised polymer, was then shown to efficiently catalyse Mizoroki–Heck reactions of aryl iodides, bromides or activated chlorides with olefins such as styrene and n-butyl acrylate in dimethylformamide. In contrast with other polymer-supported catalysts, the main advantage of this method is the low cost of the catalyst due to the simple synthetic route using easily obtained materials and good recoverability. Transmission electron microscopy and X-ray diffraction measurements were used to show the high metal dispersion and small sizes of Ni nanoparticle on the surface of the modified polymer. DPP-PVA-co-PE-NiNPs could be recycled several times.
- Ebrahimzadeh, Farzaneh
-
p. 541 - 546
(2017/10/03)
-
- 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)
-
- 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)
-
- In situ generation of highly active bis(N-heterocyclic)carbene palladium as an efficient catalyst in direct S-arylation of methylphenyl sulfoxide and the Heck reaction: Ligand steric effects in product selectivity
-
The use of 1,3-bis(N-heterocyclic)carbene ligands with different alkyl wingtip groups (alkyl = methyl, isopropyl and tert-butyl) is an effective method for the palladium-catalysed direct S-arylation of methylphenyl sulfoxide and C–C coupling of various of aryl halides with alkenes. The reactions proceed in moderate to good yields. Interestingly, it is shown experimentally that, by using bulkier bidentate N-heterocyclic carbene ligands, more selective catalytic systems towards cis products in Heck coupling reactions can be achieved.
- Bagherzadeh, Mojtaba,Mousavi, Narges-Alsadat,Jamali, Sirous
-
-
- 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)
-
- In-situ-generated palladium nanoparticles in novel ionic liquid: an efficient catalytic system for Heck–Matsuda coupling
-
Abstract: A green, convenient, ecological and recyclable method comprising dual functionalized, task-specific, ionic liquid (IL)-triggered, in situ-generated Pd nanoparticles (NPs) and their catalytic application for Heck–Matsuda coupling of olefins is described. Both arenediazonium tetrafluoroborate and silica sulphate salts are coupled with olefins under ligand-free and aerobic conditions at ambient temperature furnishing excellent yields of products. The Ionic liquid used acts as a reducing as well as stabilizing agent for in situ-generated Pd NPs. The formed NPs were characterized by transmission electron microscopy (TEM) analysis, having a size below 50?nm, and exhibited high catalytic activity. The catalytic system can be reused for eight times effectively without any significant loss of activity. The method was found to be highly stereo-specific, giving exclusively the ‘E’ isomer.
- Gaikwad,Undale,Patil,Pore,Korade,Kamble
-
p. 4445 - 4458
(2017/07/22)
-
- Cyclodextrin-Grafted Silica-Supported Pd Nanoparticles: An Efficient and Versatile Catalyst for Ligand-Free C-C Coupling and Hydrogenation
-
Silica is an extremely versatile support, which is capable of hosting metal nanoparticles (NPs) and enhancing their stability and reactivity. In this study, a novel cyclodextrin/silica support for Pd NPs, which we have denoted Pd/Si-CD, has been prepared. The highly efficient and homogeneous impregnation of small palladium nanoparticles on this support has been carried out under conventional conditions, and ultrasound irradiation has been shown to have a beneficial effect on catalyst preparation. The catalyst exhibited excellent activity in ligand-free C-C Suzuki and Heck couplings with a large number of aryl iodide and bromides, in which microwave irradiation use cuts down reaction time. Pd/Si-CD have shown high activity and selectivity in the hydrogenation reaction, and the semihydrogenation of phenyl acetylene was also studied with excellent results.
- Martina, Katia,Baricco, Francesca,Caporaso, Marina,Berlier, Gloria,Cravotto, Giancarlo
-
p. 1176 - 1184
(2016/04/05)
-
- Phosphanamine-functionalized magnetic nanoparticles (PAFMNP): An efficient magnetic recyclable ligand for the Pd-catalyzed Heck reaction of chloroarenes
-
A phosphanamine-functionalized trimethoxysilyl compound (DPPPA) was synthesized and reacted with magnetic nanoparticles in order to synthesise a novel magnetic reusable phosphanamine ligand (PAFMNP) for application in transition metal-catalyzed coupling reactions. The Pd complex of PAFMNP (Pd-PAFMNP) was found to be an efficient heterogeneous catalyst for the Heck reaction of aryl chlorides. Only 1.0 mol% of catalyst was needed to accomplish the Heck reaction of the aryl chlorides. The catalyst was reusable at least 5 times without a significant decrease in its catalytic activity.
- Panahi, Farhad,Zarnaghash, Narges,Khalafi-Nezhad, Ali
-
p. 1250 - 1255
(2016/02/19)
-
- Silver(I) and palladium(II) complexes of new pentamethylene-functionalized bis-imidazolium dication ligands and its application in Heck and Suzuki-Miyaura coupling reaction
-
Two new pentamethylene-functionalized bis-imidazolium dication ligands L1 and L2 (L1 = 1,5-bis(4-(imidazolium-1-yl-phenol)pentane dibromide; L2 = 1,5-bis(1-vinylimidazolium-1-yl)pentane dibromide) bearing IP (4-(imidazol-1-yl)phenol) and VI (1-vinylimidazole)-functionality have been prepared via the reaction of 1,5-dibromopentane with a substituted imidazole derivative. The bis-imidazolium dication ligands L1 and L2 on reaction with Ag2O in DCM:MeOH, followed by anion substitution with AgBF4 led to the formation of silver(I) complexes [Ag2(PC(CH2)5CP)2][BF4]2 (PC(CH2)5CP = 1,5-bis(4-(imidazolium-1-yl-phenol) pentane (1) and [Ag2(VC(CH2)5CV)2][BF4]2 (VC(CH2)5CV = 1,5-bis(1-vinylimidazolium-1-yl)pentane (2). Transmetalation of the bis-NHC ligand from [Ag2(PC(CH2)5CP)2][BF4]2 and [Ag2(VC(CH2)5CV)2][BF4]2 by palladium(II) salt [PdCl2(CH3CN)2] in DMSO gave [PdCl(PC(CH2)5CP)(CH3CN)]BF4 (3) and [PdCl(VC(CH2)5CV)(CH3CN)]BF4 (4), respectively. The new ligands as well as their silver(I) and palladium(II) complexes have been characterized by elemental analysis, electronic, IR, 1H and 13C NMR, and FAB-MS spectroscopy. The molecular structure of the representative ligand L1 has been determined by single crystal X-ray analysis. The palladiumII NHC complexes 3 and 4 exhibited good activity in a model Heck and Suzuki-Miyaura coupling reaction.
- Trivedi, Manoj,Bhaskaran,Singh, Gurmeet,Kumar, Abhinav,Rath, Nigam P.
-
-
- Suzuki, Stille and Heck cross-coupling reactions catalyzed by Fe3O4@PTA-Pd as a recyclable and efficient nanocatalyst in green solvents
-
The use of a supported Pd complex on magnetic nanoparticles as an efficient and green catalyst for the Suzuki, Stille and Heck cross-coupling reactions is presented. The present research is focused on investigating the recycling, reusability and stability of the catalyst in the reaction. The recycled Fe3O4@PTA-Pd catalyst was used at least five times with comparable activities to that of the fresh catalyst. The catalytic coupling of 4-bromotoluene as a model reaction suggested that there was no leached palladium in the reaction mixture. The structure of the catalyst was characterized by TGA, EDS, ICP-OES, XRD, VSM, FT-IR and SEM analysis.
- Ghorbani-Choghamarani, Arash,Norouzi, Masoomeh
-
p. 6299 - 6307
(2016/07/19)
-
- Heterogeneous Fe3O4@chitosan-Schiff base Pd nanocatalyst: Fabrication, characterization and application as highly efficient and magnetically-recoverable catalyst for Suzuki-Miyaura and Heck-Mizoroki C-C coupling reactions
-
An environmentally friendly palladium-based catalyst supported on magnetite nanoparticles was successfully prepared. FT-IR, XRD, VSM, SEM, EDS and TGA studies have been used to characterize the nanocatalyst. The catalytic activity of the as-prepared catalyst was evaluated as a heterogeneous catalyst for the Suzuki-Miyaura carbon-carbon cross-coupling reaction of aryl halides and phenylboronic acid. Furthermore, it was found that the catalyst showed a high activity for the Mizoroki-Heck reaction of aryl halides and n-butyl acrylate. Interestingly, the novel catalyst could be recovered in a facile manner from the reaction mixture and recycled consecutive five runs without any significant loss in activity.
- Naghipour,Fakhri
-
-
- Synthesis, crystal structure study and high efficient catalytic activity of di-μbromo-trans–dibromobis[(benzyl)(4-methylphenyl)(phenyl)phosphine] dipalladium(II) in Suzuki–Miyaura and Heck–Mizoroki C–C coupling reactions
-
The current research aims to present a straightforward synthesis of binuclear palladated triphenylphosphine derivative by the reaction of the phosphonium salt [(PhCH2)P(Ph)2(Ph-4-CH3)]Br with palladium(II) chloride and to afford the dimeric palladated complex {Pd[P(Ph)(CH2Ph)(Ph-4-CH3)]((μ-Br)Br)}2. Moreover, elemental analysis (CHN), FT-IR, 1H, 31P, 13C NMR and X-ray crystallography led to the characterization of the obtained compound. Finally, This compound was found to be an efficient catalyst in C–C bond formation between various aryl halides with phenylboronic acid (Suzuki–Miyaura reaction) and aryl halides with n-butyl acrylate (Heck–Mizoroki reaction).
- Ghorbani-Choghamarani, Arash,Naghipour, Ali,Babaee, Heshmatollah,Notash, Behrouz
-
p. 517 - 524
(2016/10/25)
-
- Palladium-Schiff Base Complex Immobilized Covalently on Magnetic Nanoparticles as an Efficient and Recyclable Catalyst for Heck and Suzuki Cross-Coupling Reactions
-
A new palladium-Schiff base complex immobilized covalently on magnetic nanoparticles (Pd-imino-Py-γ-Fe2O3) was synthesized via the reaction of chloro-functionalized γ-Fe2O3 with iminopyridine followed by the reaction with palladium acetate. Characterization of Pd-imino-Py-γ-Fe2O3 was carried out by various techniques such as XRD, SEM, TEM, FT-IR, TGA, ICP, XPS, VSM and elemental analysis. Pd-imino-Py-γ-Fe2O3 was successfully applied as a magnetically recyclable heterogeneous catalyst in Heck and Suzuki cross-coupling reactions of various aryl halides (iodide, bromides and chlorides as challenging substrates) with olefins and phenylboronic acid, respectively. The synthesized catalyst was separated easily by using an external magnet and recycled eight runs without appreciable loss of its catalytic activity and leaching of the significant quantity of Pd. Graphical Abstract: [Figure not available: see fulltext.]
- Sobhani, Sara,Falatooni, Zahra Mesbah,Asadi, Solmaz,Honarmand, Moones
-
p. 255 - 268
(2016/02/23)
-
- Green and efficient procedure for Suzuki-Miyaura and Mizoroki-Heck coupling reactions using palladium catalyst supported on phosphine functionalized ZrO2 NPs (ZrO2@ECP-Pd) as a new reusable nanocatalyst
-
In this article, palladium supported on phosphine functionalized ZrO2 NPs (ZrO2@ECP-Pd) has been introduced as a novel and efficient nanocatalyst for Suzuki-Miyaura and Mizoroki-Heck reactions. This new catalyst was prepared from the reaction of Pd(OAc)2 and PPh2-functionalized ZrO2 NPs, and then characterized using FT-IR, XRD, SEM, TEM, TGA and ICP techniques. The above experimental results showed that the synthesized catalyst existed as spheres with a mean size range of 10-40 nm. The prepared ZrO2@ECP-Pd nanocatalyst was shown to be highly efficient in the Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions of a wide range of aryl halides including electron-rich and electron-poor aryl iodides/bromides, and heteroaryl iodides, affording the corresponding products in good to excellent yields in short reaction times. The notable feature of the present protocol is the use of water and [bmim]PF6 as environmentally benign solvents, which eliminate the need of toxic solvent. In addition to the aforementioned favorable properties, the nanocatalyst can be recovered and reused for the subsequent reactions (at least six times) without any appreciable loss of efficiency.
- Zarghani, Monireh,Akhlaghinia, Batool
-
p. 1192 - 1200
(2016/11/02)
-
- Catalysis by metal nanoparticles dispersed within a hierarchically porous carbon material
-
Disclosed are hierarchically porous carbon materials with a plurality of discreet nanoparticles dispersed on their carbon phase. The materials possess a continuous network of pores that spans the porous material, permitting the flow of fluids into and thr
- -
-
-
- Palladiumimmobilized on chitosan nanofibers cross-linked by glutaraldehyde as an efficient catalyst for the Mizoroki–Heck reaction
-
Nonwoven chitosan (CS) nanofiber mats were successfully prepared by the electrospinning of the mixture of CS and poly(ethylene oxide) (PEO) in acetic acid aqueous solution. The CS/PEO fiber mats were treated with glutaraldehyde aqueous solution to stabili
- Wang,Xu,Shao,Qi
-
p. 354 - 359
(2016/07/06)
-
- Immobilized Pd(0) nanoparticles on phosphine-functionalized graphene as a highly active catalyst for Heck, Suzuki and N-arylation reactions
-
In this study, a phosphine group was chemically grafted to the surface of graphene in order to prepare a reusable ligand with high surface area, incorporating a phosphine moiety. The treatment of graphene oxide (GO) with hydroxide followed by an aqueous work-up yields an OH-functionalized graphene material (GOH) via ring-opening of the epoxide groups. Reaction of GOH with chlorodiphenylphosphine (ClPPh2) gives a new material, GOPPh2 (PFG), which can be used for stabilization of metal nanoparticles or complexation of transition metals in order to prepare a reusable metal catalyst. Stabilization of palladium nanoparticles on the surface of GOPPh2 resulted in the production of an efficient heterogeneous Pd catalyst (PFG-Pd) for application in C-C and C-N bond formation reactions. The PFG-Pd catalyst was characterized using some different microscopic and spectroscopic techniques such as FT-IR, XRD, TEM, SEM, EDX, and ICP analysis. The applicability of the PFG-Pd catalyst was evaluated in Heck, Suzuki and N-arylation reactions. The catalyst system showed high catalyst activity in these processes and the target products were obtained in high isolated yields. The PFG-Pd catalyst was reusable in these reactions for at least 5 times with no significant decrease in its catalytic activity.
- Fareghi-Alamdari, Reza,Haqiqi, Mohsen G.,Zekri, Negar
-
p. 1287 - 1296
(2016/02/19)
-
- Maghemite decorated with ultra-small palladium nanoparticles (γ-Fe2O3-Pd): Applications in the Heck-Mizoroki olefination, Suzuki reaction and allylic oxidation of alkenes
-
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.
- 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)
-
- N-Acylsaccharins as Amide-Based Arylating Reagents via Chemoselective N-C Cleavage: Pd-Catalyzed Decarbonylative Heck Reaction
-
Palladium-catalyzed decarbonylative Heck reaction of amides by chemoselective N-C activation using N-acylsaccharins as coupling partners has been accomplished. These studies represent only the second example of amide-Heck reactions reported to date. A broad range of electronically diverse amide and olefin coupling partners is amenable to this transformation. Orthogonal site-selective Heck cross-couplings by C-Br/N-C cleavage and mechanistic studies are reported. This report introduces readily available, bench-stable, cheap, and benign N-acylsaccharins as aryl transfer reagents to access versatile aryl-metal intermediates.
- Liu, Chengwei,Meng, Guangrong,Szostak, Michal
-
p. 12023 - 12030
(2016/12/09)
-
- 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
-
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.
- 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)
-
- Compositions containing ionic liquids and their uses, in particular in organic synthesis
-
An ionic liquid is used as liquid matrix for organic synthesis in homogeneous phase on soluble support, the ionic liquid being presented in liquid or solid form at ambient temperature, of formula A1+X1?, A1+ representing a cation, functional or non-functional, or a mixture of cations in which either none of the cations is functional or at least one of the cations is functional, and X1? an anion, functional or non-functional, or a mixture of anions in which either none of the anions is functional or at least one of the anions is functional.
- -
-
Page/Page column 45; 46; 47; 50
(2016/10/17)
-