Mizoroki Heck Coupling Reaction Research Articles

Palladium nanoparticles immobilized on amphiphilic and hyperbranched polymer‐functionalized magnetic nanoparticles: An efficient semi‐heterogeneous catalyst for Heck reaction

To address the obstacles facing the use of palladium‐based homogeneous and heterogeneous catalysts in C─C cross‐coupling reactions, a novel semi‐heterogeneous support was developed based on hyperbranched poly(ethylene glycol)‐block‐poly(citric acid)‐functionalized Fe3O4 magnetic nanoparticles (Fe3O4@PCA‐b‐PEG). Because of the surface modification of the Fe3O4 nanoparticles with amphiphilic and hyperbranched polymers (PCA‐b‐PEG), these hybrid materials are not only soluble in a wide range of solvents (e.g. water, ethanol and dimethylformamide) but also are able to trap Pd2+ ions via complex formation of free carboxyl groups of the PCA dendrimer with metal ions. The reduction of trapped palladium ions in the dendritic shell of Fe3O4@PCA‐b‐PEG leads to immobilized palladium nanoparticles. The morphology and structural features of the catalyst were characterized using various microscopic and spectroscopic techniques. The catalyst was effectively used in the palladium‐catalysed Mizoroki–Heck coupling reaction in water as a green solvent. In addition, the catalyst can be easily recovered from the reaction mixture by applying an external magnetic field and reused for more than ten consecutive cycles without much loss in activity, exhibiting an example of a sustainable and green methodology.

Palladium nanoparticles immobilized on a magnetic chitosan-anchored Schiff base: applications in Suzuki–Miyaura and Heck–Mizoroki coupling reactions

A palladium nanocatalyst Fe3O4@CS-SB-Pd has been synthesized and characterized by FT-IR, XRD, XPS, FESEM, EDX, TEM, TGA, and ICP-AES analysis.

Monodentate palladium(0)–[60]fullerene complexes of diphosphine ligands as efficient and sustainable nanocatalysts for the Mizoroki–Heck coupling reaction of aryl chlorides

The present article combines fullerene chemistry with phosphine-based Pd catalytic systems to report new palladium(0)–[60]fullerenes as heterogeneous nanocatalysts for C–C bond transformations of aryl chlorides.

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.

Fe3O4@SiO2 Nanoparticles Decorated with Schiff base Complex of Pd(II) as a Magnetically Phosphine-free Catalyst for Heck-Mizoroki Coupling Reactions

Background: The palladium-catalyzed couplings of alkenes with aryl halides is considered as one of the most important methods for carbon-carbon bond formation and have been utilized in the areas of natural products, high performance materials, bioactive compounds, new drugs and many industrially useful chemicals. Although the homogeneous palladium catalysts offer several advantages concerning higher selectivity and yields, better tuning of chemoselectivity and high efficiency but commercializing most of homogeneous has not been possible because of recycling problem of the catalyst from the mixture of reaction. Therefore, for resolving this problem, immobilization of homogeneous Pd complexes via grafting to solid supports such as activated carbon, zeolites, silica or modified silica, polymers, nanoparticles, and magnetic core shells have been subject of great challenges. Methods: Fe3O4 nanoparticles was coated by silica gel and then decorated by Schiff base Pd complex to provide Fe3O4@SiO2/Schiff base/Pd(II) nanoparticles. After optimization of reaction parameters, Heck- Mizoroki coupling reaction of aryl halides with olefins was studied. Results: The magnetic Schiff base complex of Pd, as a phosphine free nanocatalyst, catalyzed efficiently Heck-Mizoroki carbon-carbon coupling reaction between aryl halides and alkenes and provided the desired products in high yields. The magnetic Pd complex was easily removed from the reaction mixture and reused for eight runs. Conclusion: A new efficient, simple and cost effective protocol was introduced for carbon-carbon bond formation via Heck-Mizoroki coupling reaction of aryl halides with olefins in high to excellent yields in short reaction times. These valuable advantages were achieved because of employing Fe3O4@SiO2/Schiff base/Pd(II) complex as a dispersible, phosphine free ligand, highly active, magnetically recoverable and reusable several times. Keywords: Aryl halides, C- C coupling, heck reaction, magnetic nanoparticles, n-butyl acrylate palladium Styrene.

A silica-supported palladium-bis(oxazoline) complex efficiently catalyzes the synthesis of cinnamic acid derivatives via Mizoroki–Heck coupling reactions

A palladium(II)-bis(oxazoline) complex supported on silica (Pd-BOX-Si) was prepared, characterized and applied as a catalyst in Mizoroki–Heck cross-coupling reactions. The bis(oxazoline) (BOX) ligand has a hydroxyl group that can be anchored to 4-benzyl chloride-functionalized silica gel, followed by the coordination of palladium(II) chloride. The catalytic activity and the recyclability of Pd-BOX-Si have been investigated in the production of cinnamic acid derivatives via Mizoroki–Heck coupling reactions of acrylates with aryl halides; The Pd-BOX-Si catalyst demonstrated excellent catalytic activity. Characterization of the recycled Pd-BOX-Si catalyst revealed its good stability under the reaction conditions employed.

The effect of framework functionality on the catalytic activation of supported Pd nanoparticles in the Mizoroki–Heck coupling reaction

Palladium nanoparticles (Pd-NPs) were supported on functional and nonfunctional Co-coordination polymers (Pd/CoBDCNH 2 and Pd/CoBDC). Advanced analytical techniques revealed that Pd-NPs are supported on the external surface of the polymer framework and the functionalized framework possesses effective influence to prevent Pd-NP aggregation. Supported Pd-NPs were effectively applied as heterogeneous recyclable catalysts in the Mizoroki–Heck C–C cross coupling reactions of iodobenzene and either aromatic or aliphatic terminal alkenes. Catalytic results exhibited that highly dispersed Pd-NPs with low loading (1%) on the functional polymer (Pd/CoBDCNH 2 ) are more effective than aggregated Pd-NPs with high loading (9%) on the nonfunctional polymer (Pd/CoBDC). Both catalysts can simultaneously provide high activity and selectivity to E-coupled products, high efficiency in low amounts, easy separation of heterogeneous catalyst and appropriate performance in the recycling reaction without addition of a reducing agent.

Terephthalic acid derived ligand‐stabilized palladium nanocomposite catalyst for Heck coupling reaction: without surface‐modified heterogeneous catalyst

A new protocol is reported for the synthesis of a heterogeneous palladium nanocomposite stabilized with a terephthalic acid‐derived ligand (N,N‐bis(4‐hydroxy‐3‐methoxybenzylidene)terephthalohydrazide). This is a highly insoluble ligand in common organic solvents, except dimethylformamide and dimethylsulfoxide. The resulting palladium nanocomposite acts as an efficient catalyst precursor for Mizoroki–Heck coupling reactions conducted under various reaction conditions. The spectral data suggest that the rate, yield and recycling of the catalyst are more effective for C–C coupling reactions. Copyright © 2016 John Wiley & Sons, Ltd.

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

Abstract 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.

Benzimidazol-2-ylidene ligated palladacyclic complexes of N,N-dimethylbenzylamine – Synthesis and application to C–C coupling reactions

Palladacyclic complexes derived from N,N-dimethylbenzylamine (dmba) and the benzimidazol-2-ylidene ligands: 1,3-di(cyclohexyl)benzimidazol-2-ylidene (BzImCy), 1,3-di(tert-butyl)benzimidazol-2-ylidene (BzImtBu) and 1,3-di(1-adamantyl)benzimidazol-2-ylidene (BzImAd) were prepared. The yield for (BzImCy)Pd(Cl)dmba (2a) was 72% but yields for the more sterically encumbering analogues: (BzImAd)Pd(Cl)dmba (2b) and (BzImtBu)Pd(Cl)dmba (2c) were 34% and 38%, respectively. The complexes were obtained as off-white, moisture- and air-stable crystalline solids and were characterized by 1H NMR and 13C NMR spectroscopy, CHN analysis and IR spectroscopy. Complex 2c was further characterized by X-ray diffraction studies. The catalytic activity of all three complexes was explored for the Suzuki–Miyaura and Heck–Mizoroki coupling reactions of simple aryl bromides.

ChemInform Abstract: An Expedient Approach to Enhance Mizoroki—Heck Coupling Reaction by Infrared Irradiation Using Palladacycle Compounds.

An alternative and environmentally friendly strategy to promote the Mizoroki–Heck cross-coupling reaction by the use of infrared irradiation using palladacycles as precatalysts is reported. Coupling products are obtained in high yield and short reaction time. A comparison with the classical use of reflux conditions, and commercial sources of palladium complexes, shows the advantages of this new alternative for promoting coupling reactions. Copyright © 2015 John Wiley & Sons, Ltd.

Palladium supported on diaminoglyoxime‐functionalized Fe3O4 nanoparticles as a magnetically separable nanocatalyst in Heck coupling reaction

A hybrid material of palladium supported on diaminoglyoxime‐functionalized Fe3O4 was used as an effective and recyclable catalyst in Mizoroki–Heck coupling reactions. The catalyst was very effective for the Mizoroki–Heck reaction of aryl halides with styrene and conversion was in most cases excellent. The yields of the products were in the range 75–98%. The catalyst showed good stability and could be recovered and reused for six reaction cycles without significant leaching and loss its catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd.

Trimetallic PEPPSI‐Type Palladium N‐Heterocyclic Carbene Complexes – Improved Catalyst Lifetime in the Mizoroki–Heck Coupling Reaction

AbstractA series of mono‐ and dendritic trimetallic PEPPSI‐type (pyridine‐enhanced precatalyst preparation stabilization and initiation) complexes bearing N‐heterocyclic carbene (NHC) ligands containing a protected amine in the form of an ethylphthalimido group have been synthesized. These discrete prototypes of complexes covalently bound to suitable supports have been studied in the Mizoroki–Heck coupling of aryl iodides under mild conditions, including sets of experiments to assess the lifetime of the active species. The palladated dendrons are more efficient and robust catalysts than their monometallic counterparts.

Palladium(0) complexes of N-heterocyclic carbene ligands with dangling NMeC[dbnd]O functionalities: Synthesis, reactivity and application in Mizoroki–Heck reactions

A series of new Pd(0) complexes of N-heterocyclic carbene (NHC) ligands with dangling NMe(CO) functionalities (LMe) is reported, with yields in the range 56–73%. The reactivity of one of the Pd(0) complexes, bearing bulky N-mesityl groups, towards the oxidative addition of pentafluoroiodobenzene was studied, revealing the formation of decafluorobiphenyl, a diiodo Pd(II) NHC complex and an intriguing Pd(II) complex with four carbon-donor ligands coordinated to the metal center. The latter complex contains two new NHC ligands derived from LMe. One of the NHC ligands is a bidentate ligand, resulting from an addition reaction between LMe and the coordinated maleic anhydride. The other NHC ligand is derived from the N-protonation of LMe. A pentafluorophenyl ligand completes the fourth coordination site. A mechanism for the formation of this intriguing Pd(II) complex is proposed. The structures of these two new Pd(II) complexes were established by single-crystal X-ray diffraction studies. The catalytic activities of the new Pd(0) complex with LMe in the Mizoroki–Heck coupling reaction between 4-chloroacetophenone and styrene were compared and they contrast with those reported for the Pd(0) NHC complex with dangling NH(CO) groups (LH).

An expedient approach to enhance Mizoroki–Heck coupling reaction by infrared irradiation using palladacycle compounds

An alternative and environmentally friendly strategy to promote the Mizoroki–Heck cross‐coupling reaction by the use of infrared irradiation using palladacycles as precatalysts is reported. Coupling products are obtained in high yield and short reaction time. A comparison with the classical use of reflux conditions, and commercial sources of palladium complexes, shows the advantages of this new alternative for promoting coupling reactions. Copyright © 2015 John Wiley & Sons, Ltd.

A highly active palladium(II)–bis(oxazoline) catalyst for Suzuki–Miyaura, Mizoroki–Heck and sonogashira coupling reactions in aqueous dimethylformamide

An efficient catalytic system based on a new palladium–bis(oxazoline) (Pd-BOX-1) complex has been developed. The complex Pd-BOX-1 adopts a legless chair‐type structure where the distorted square planar [PdN2Cl2] moiety and the benzene ring spacer represent the seat and the chair back, respectively. The catalytic activity of Pd-BOX-1 has been investigated in dimethylformamide–water under aerobic and mild conditions in Suzuki–Miyaura coupling reactions of arylboronic acids with aryl iodides, aryl bromides and aryl chlorides, Mizoroki–Heck coupling reactions of aryl halides with styrene derivatives, and Sonogashira coupling reactions of aryl halides with terminal alkynes. A wide range of functional groups as substituents on the arylboronic acids and aryl halides were considered. Pd-BOX-1 demonstrates exceptional air and moisture stability. Of note, the catalyst system based on Pd-BOX-1 shows high recycling ability in Suzuki–Miyaura coupling reactions in dimethylformamide–water without any loss in catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd.

A simple TLC-densitometric method for the quantification of acrylic acid in aqueous solutions

Because acrylic acid is a volatile organic compound, the precise quantification of acrylic acid by thin-layer chromatography (TLC) analysis is difficult. Herein, we report a simple TLC–densitometric method for the quantification of acrylic acid in aqueous solutions following a labeling procedure using the Mizoroki-Heck coupling reaction. To make acrylic acid nonvolatile and highly sensitive for ultraviolet (UV) detection, acrylic acid in an aqueous solution was reacted with iodobenzene in a dimethyl sulfoxide solution using a base (potassium carbonate) and a catalyst (FibreCat 1001), affording trans-cinnamic acid. High-performance liquid chromatography (HPLC) analysis showed that acrylic acid could be labeled over a range of 0.01–10 mM at 60°C for 30 min and the average reaction yield was 96.0%. To quantify acrylic acid by TLC analysis, the reaction mixture was extracted using ethyl acetate and then spotted on a silica gel 60 F254 TLC plate. The spots corresponding to the labeled acrylic acid over a range...

Palladium nanoparticles on β-cyclodextrin functionalised graphene nanosheets: a supramolecular based heterogeneous catalyst for C–C coupling reactions under green reaction conditions

Palladium nanoparticles on β-cyclodextrin functionalised graphene based supramolecular heterogeneous catalyst are used for Suzuki–Miyaura and Heck–Mizoroki coupling reactions under green reaction conditions.

Investigation of Mizoroki-Heck coupling polymerization as a catalyst-transfer condensation polymerization for synthesis of poly(p-phenylenevinylene)

Mizoroki-Heck coupling polymerization of 1,4-bis[(2-ethylhexyl)oxy]-2-iodo-5-vinylbenzene (1) and its bromo counterpart 2 with a Pd initiator for the synthesis of poly(phenylenevinylene) (PPV) was investigated to see whether the polymerization proceeds in a chain-growth polymerization manner. The polymerization of 1 with tBu3PPd(Tolyl)Br (10) proceeded even at room temperature when 5.5 equiv of Cy2NMe (Cy = cyclohexyl) was used as a base, but the molecular weight distribution of PPV was broad. The polymerization of 2 hardly proceeded at room temperature under the same conditions. In the polymerization of 1, PPV with H at one end and I at the other was formed until the middle stage, and the polymer end groups were converted into tolyl and H in the final stage. The number-average molecular weight (Mn) did not increase until about 90% monomer conversion and then sharply increased after that, indicating conventional step-growth polymerization. The occurrence of step-growth polymerization, not catalyst-transfer chain-growth polymerization, may be interpreted in terms of low coordination ability of H-Pd(II)-X(tBu3P) (X = Br or I), formed in the catalytic cycle of the Mizoroki-Heck coupling reaction, to π-electrons of the PPV backbone; reductive elimination of H-X from this Pd species with base would take place after diffusion into the reaction mixture. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 543–551

Application of the Palladium‐Catalysed Norbornene‐Assisted Catellani Reaction Towards the Total Synthesis of (+)‐Linoxepin and Isolinoxepin

Scheme 18 on page 4061 of the original article1 was inadvertently replaced by a copy of Scheme 17. The correct Scheme 18 is given below. We apologize for this error. The Editors Synthesis of (±)-linoxepin (1) by the Mizoroki–Heck coupling reaction. Reagents and conditions: a) Pd(OAc)2 (10 mol-%), PPh3 (20 mol-%), HO2CNa (10 equiv.), DMF/MeCN (1:1), r.t. to 55 °C overnight.