Catalyst For Suzuki-Miyaura Coupling Research Articles

Towards Nickel-NHC Fluoro Complexes-Synthesis of Imidazolium Fluorides and Their Reactions with Nickelocene.

While hundreds of complexes of the general formula [Ni(η5-C5H5)(NHC)(X)] exist (NHC = a N-heterocyclic carbene, X = Cl, Br, I), none is yet known with X = F. We attempted to prepare such a species by reacting nickelocene with imidazolium fluorides. Three imidazolium fluorides (ImH)+ F- [Im = (N,N'-bis-(R)-imidazolium: 1a, IMe, R = Me; 1b, IMes, R = 2,4,6-trimethylphenyl; 1c, IPr, R = 2,6-diisopropylphenyl)] were prepared and characterized by spectroscopic methods. In addition, the salts 1b [(IMesH)+ F-] and 1c [(IPrH)+ F-] were subjected single-crystal X-ray diffraction experiments. The reactions of these imidazolium fluorides with nickelocene did not lead to [Ni(η5-C5H5)(NHC)(F)] species. Instead, the reaction of 1a [(IMeH)+ F-] and 1b [(IMesH)+ F-] with nickelocene led to the salt 2 [Ni(η5-C5H5)(IMe)2]+ F- and to the square planar complex 3atrans-[NiF2(IMes)2] respectively. Both complexes were characterized spectroscopically and by single crystal X-ray diffraction. All four X-ray diffraction studies reveal hydrogen bonding and hydrogen interactions with the F atom or anion, and in some cases with solvent molecules of crystallization, and these phenomena are all discussed. Complex 2, in particular, exhibited a wide range of interesting H-bonded interactions in the solid state. Complexes 2 and 3a were tested as catalysts for Suzuki-Miyaura coupling but were not promising: complex 2 was inactive, and while 3a did indeed catalyze the reaction, it gave widely diverging results owing to its instability in solution.

Continuous-Flow Suzuki-Miyaura Coupling in Water and Organic Solvents Promoted by Blends of Stabilized Convoluted Polymeric Palladium Catalysts and Polymeric Auxiliary Materials.

Given that heterogeneous palladium-catalyzed C-C bond formation reactions under continuous-flow conditions are well suited for the efficient and safe production of pharmaceuticals and functional materials, the development of active and durable catalysts for this purpose is a matter of high practical significance. Here, a previously established molecular convolution methodology was used to synthesize catalysts for Suzuki-Miyaura coupling under flow conditions by blending convoluted polymeric palladium catalysts (prepared from copolymers of 4-vinylpyridine and 4-tert-butylstyrene) and crosslinked polymeric auxiliary materials (prepared from copolymers of divinylbenzene and 4-tert-butylstyrene). The optimal catalyst exhibited high performance and durability and allowed numerous biaryl products such as liquid-crystalline materials, organic electroluminescent materials, and pharmaceuticals to be continuously synthesized with turnover frequencies of up to 238 h-1 . In a demonstration of practical utility, the developed catalytic system was used for the continuous synthesis of two pharmaceuticals (felbinac and fenbufen) in water as the sole solvent.

Mechanistic insights and computational design of Cu/M bimetallic synergistic catalysts for Suzuki-Miyaura coupling of arylboronic esters with alkyl halides

Carbonylative Suzuki-Miyura coupling reaction is one of the most efficient methods to synthetize ketones. In this work, the reaction mechanism of arylboronic esters with alkyl halides catalyzed by Cu/Mn synergistic catalysts has been studied by DFT calculation. The calculated results show that the whole reaction contains two cycles, one is the Cu-catalyzed transformation of Ar-Bneop to RO-Bneop, and the other is Mn-catalyzed Heck–Breslow cycle for alkyl halide carbonylation. At the last step, the final product aryl ketone is produced through the C-C cross-coupling between the two intermediates, which form from the above separate two cycles. For the title reaction, the [Mn(CO)5]− catalyzed the Heck–Breslow cycle belongs to SN2 mechanism, and Mn2(CO)10 catalyzed cycle is SET mechanism. In addition to [Mn(CO)5]−, the metal carbonyl anions with moderate even low nucleophilicity are suitable to co-catalyze the carbonylative Suzuki-Miyaura coupling with the Cu-carbene catalyst. Our calculation results are consistent with and provide explanations the experimental observations, as well as shed lights on further advancement of new bimetallic catalysts.

Mechanistic Insights and Computational Design of Cu/M Bimetallic Synergistic Catalysts for Suzuki-Miyaura Coupling of Arylboronic Esters with Alkyl Halides

Mechanistic Insights and Computational Design of Cu/M Bimetallic Synergistic Catalysts for Suzuki-Miyaura Coupling of Arylboronic Esters with Alkyl Halides

Novel Recyclable Pd/H-MOR Catalyst for Suzuki-Miyaura Coupling and Application in the Synthesis of Crizotinib

In this paper, we report an effective ultrasound method for the synthesis of Pd/H-MOR, which was used as a catalyst in the Suzuki-Miyaura coupling of aryl halides with phenylboronic acid. The structure and morphology of the as-prepared catalysts were fully characterized by X-ray diffraction (XRD), N2 sorption isotherms, scanning electron microscopy (SEM), and an inductively coupled plasma-atomic emission spectrometer (ICP-AES). The advantages of Pd/H-MOR in the coupling reaction are green solvents, high yields, absence of ligands, and recyclability. The catalysts were easily reused at least ten times without significant deterioration in catalytic activity. In addition, this protocol was used in the marketed anti-tumor drug crizotinib synthesis.

An incredible magnetic Pd/CuFe2O4 catalyst for low-temperature aqueous Suzuki-Miyaura coupling

In this investigation, a magnetic catalyst system based on CuFe2O4 was conveniently synthesised using citrate-gel method followed by wet impregnation. The synthesised compound was thoroughly characterised using XRD, XPS, IR, SEM-EDAX, TEM VSM and ICP-AES. It was then utilised for catalytic Suzuki-Miyaura coupling yielding excellent results. We thus report a remarkably efficient ligand-free magnetic Pd catalyst for Suzuki-Miyaura coupling in aqueous medium. Here the amount of Pd utilised is as low as 0.00047 mol% in terms of aryl iodide used. The catalyst showed unaltered activity for five consecutive cycles with an average yield of 89.6% with the model substrate.

A highly efficient and recyclable NiCl2(dppp)/PEG-400 system for Suzuki-Miyaura reaction of aryl chlorides with arylboronic acids

NiCl2(dppp) in PEG-400 is shown to be a highly efficient catalyst for Suzuki-Miyaura coupling of aryl chlorides with arylboronic acids. The reaction could be conducted at 100 °C using K3PO4 as base, yielding a variety of biaryls in good to excellent yields. The isolation of the products was readily performed by extraction with petroleum ether and NiCl2(dppp)/PEG-400 system could be easily recycled and reused up to five times without significant loss of activity. Our system not only avoids the use of easily volatile and toxic dioxane or toluene as a solvent but also solves the basic problem of nickel catalyst reuse.

Dinuclear Pd(II) complexes containing bis-O,N-bidentate Schiff base ligands: Synthesis, characterization, DFT study and application as Suzuki–Miyaura coupling catalysts

The reaction of binucleating Schiff base ligands with [PdCl2(PPh3)2] and [Pd(OAc)2] afforded a new family of binuclear palladium(II) Schiff base complexes of the type [Pd2(L)2] and [Pd2Cl2(PPh3)2(L)]. All the palladium complexes are air stable and fully characterized by elemental analysis, FT-IR, UV–Vis and 1H NMR spectral methods. These palladium(II) Schiff base complexes exhibit characteristic metal to ligand charge transfer (MLCT) transitions. Quantum mechanical calculations were also performed to investigate the electronic structure, assign the vibrational spectra and to determine the nature of the frontier molecular orbitals and absorption spectra of the above complexes. These palladium(II) Schiff base complexes exhibited good catalytic activity in the carbon–carbon Suzuki coupling reaction of different aryl halides using phenyl boronic acid.

Green synthesis and characterization of palladium nanoparticles supported on zeolite Y by sonochemical method, powerful and efficient catalyst for Suzuki‐Miyaura coupling of aryl halides with phenylboronic acid

In this paper, we report effective, useful and environmental compatible ultrasound method for the synthesis of zeolite–Y. Then, the prepared product was composed with palladium nanoparticles by sonication treatment. The prepared zeolite Y–Pd nanoparticles was used as catalyst in Suzuki‐Miyaura coupling of aryl halides (Ar‐X, X = I, Br, Cl, F) with phenylboronic acid. Based on our studies, the prepared zeolite Y‐Palladium nanoparticles revealed a high catalytic performance in Suzuki‐Miyaura coupling reaction so that aryl fluoride can even react with phenylboronic acid by utilizing this catalyst. The advantages of the use of this catalyst in Suzuki‐Miyaura coupling reaction are green solvent, short reaction time, high yields, ligandless and recyclable. Structure and morphology of the synthesized zeolite‐Y and zeolite‐Y‐Palladium nanoparticles were characterized by FT‐IR (Fourier transform infrared), XRD (X‐ray diffraction), SEM (Scanning electron microscopy), TEM (Transmission electron microscopy), EDX (Energy dispersive analysis of X‐ray), BET (Brunauer Emmett Teller) and ICP‐MS (Inductively coupled plasma mass spectrometry).

Picolinamide modified β-cyclodextrin/Pd (II) complex: Asupramolecular catalyst for Suzuki-Miyaura coupling of aryl, benzyl and allyl halides with arylboronic acids in water

Novel supramolecular catalysts for Suzuki-Miyaura coupling were prepared and characterized by NMR, FT-IR, TEM, XRD, TGA, and XPS. The resulting picolinamide-modified β-cyclodextrin/Pd(II) complex (Pd(II)@PCA-β-CD) showed very efficient catalytic activity for Suzuki-Miyaura coupling of aryl, benzyl, and allyl halides with arylboronic acids in an environmentally benign aqueous solution. Various organic halides including chlorides can produce good to excellent yields with phenyl-boronic acid and a catalytic amount of Pd(II)@PCA-β-CD. This hydro-soluble catalyst was capable of being reused for at least eight runs with only a slight loss of catalytic activity. A putative mechanism of the Pd(II)/Pd(IV) catalytic cycle was also explored and calculated by ab initio QM/MM methods.

Coordination-polymer anchored single-site ‘Pd-NHC’ catalyst for Suzuki-Miyaura coupling in water

A single-site, heterogeneous Pd–NHC-based catalyst was designed on a coordination polymer platform via metal-terpyridine interaction. The catalyst was successfully applied in Suzuki-Miyaura coupling in water showing good activity and reusability. SYNOPSIS A single-site, heterogeneous Pd–NHC-based catalyst anchored on a coordination polymer platform was successfully applied in Suzuki-Miyaura coupling in water showing good activity and reusability.

Urea‐based amphiphilic porous organic polymer‐supported palladium as a reusable catalyst for Suzuki–Miyaura coupling and hydroxycarbonylation reactions in water

The development of environmentally friendly heterogeneous catalysts for organic reactions in water is becoming of growing importance for the development of sustainable processes. In this work, a porous organic polymer‐supported palladium catalyst (Pd@UPOP‐1) was successfully fabricated from 3,3′‐diaminobenzidine and methylenediphenyl diisocyanate through a facile urea‐forming condensation reaction. The structure and composition of the catalyst were characterized using several physicochemical methods. Pd@UPOP‐1 was found to possess good porous structure and excellent amphiphilicity. Under mild reaction conditions, the catalyst showed excellent catalytic activity and good substrate compatibility for the Suzuki–Miyaura coupling reaction of aryl bromides, as well as the hydroxycarbonylation reaction of aryl iodides. In addition, the catalyst could be used for several consecutive recycles in both cases.

Visible-Light-Enabled Preparation of Palladium Nanoparticles and Application as Catalysts for Suzuki-Miyaura Coupling.

Silyl ketones were used for the preparation of palladium nanoparticles (PdNPs) starting with Pd(OAc)2 in dimethylformamide under irradiation with a visible light-emitting diode (LED). Variation of the silyl ketone structure allowed adjustment of the PdNP diameter (1.9 or 5.2 nm). The in situ-formed PdNPs were further stabilized with polyvinylpyrrolidone and then applied as recyclable catalysts in the Suzuki-Miyaura coupling of arylboronic acids with aryl iodides to obtain substituted biphenyls in excellent yields.

Porphyrin-based porous polyimide polymer/Pd nanoparticle composites as efficient catalysts for Suzuki–Miyaura coupling reactions

Two porphyrin-based porous polyimide polymer/Pd nanoparticle composites were synthesized, which exhibit high stability and excellent catalytic efficiency as Suzuki–Miyaura coupling catalysts.

Palladium(II) complexes with diaminomaleonitrile-based Schiff-base ligands: Synthesis, characterization and application as Suzuki–Miyaura coupling catalysts

The characterization of synthesized Schiff base ligands (L1–L5); (where L1=N-salicyliden- 2,3-diamino-cis-2-butenedinitrile, L2=3- methoxy-N-salicyliden-2,3-diamino-cis-2-butenedinitrile, L3=5-bromo-N-salicyliden-2,3-diamino-cis-2-butenedinitrile, L4=5-nitro-N-salicyliden-2,3-diamino-cis-2-butenedinitrile, and L5=5-methoxy-N-salicyliden-2,3-diamino-cis-2-butenedinitrile) and their palladium complexes [PdL(PPh3)] (L1–L5) were carried out by FT-IR, UV–vis, 1H NMR, 13C NMR and elemental analysis. The coordination geometry of [PdL3(PPh3)] was determined by single crystal X-ray crystallography. In this structure the palladium center was in a partially distorted NNOP square planar coordination environment. The catalytic potential of the synthesized complexes was evaluated in Suzuki–Miyaura cross-coupling reaction by choosing different arylhalides and phenylboronic acid. The results showed that arylhalides with electron withdrawing substituents were more appropriate in this reaction. In all cases, the desired product of cross coupling Suzuki reaction was the major product. It is also worth to mention that the product of homo-coupling reaction was also observed as a minor product. In this regards, a blank reaction with just phenylboronic acid was performed and the results showed the occurrence of the homo-coupling product in a good yield.

Boron Nitride Nanosheet-Anchored Pd-Fe Core-Shell Nanoparticles as Highly Efficient Catalysts for Suzuki-Miyaura Coupling Reactions.

Boron nitride nanosheets (BNNS) were used to anchor bimetallic Pd-Fe nanoparticles for Suzuki-Miyaura coupling catalysts. The bimetallic nanoparticles were found to be core-shell in structure, and their formation was likely facilitated by their interactions with the BNNS. The Pd-Fe/BNNS catalysts were highly effective in representative Suzuki-Miyaura reactions, with performances matching or exceeding those of the state-of-the-art methods. Specifically, the superior catalytic activities were characterized by generally shortened reaction times, minimal Pd usage, excellent reusability of the catalysts and high or nearly quantitative conversion yields in a benign solvent system without the need for any special conditions, such as ligands and surfactants or inert gas protection. The obvious advantages of the Pd-Fe/BNNS over similar catalysts based on other supports, such as reduced graphene oxide (rGO), suggest that BNNS may be developed into a versatile platform for many other important catalytic reactions.

A highly efficient and recyclable Pd(II) metallogel catalyst: A new scaffold for Suzuki-Miyaura coupling

A convenient and practical procedure to prepare Pd(II) metallogel as a highly efficient and recyclable catalyst for Suzuki-Miyaura coupling has been developed. Such metallogel shows highly processable and reversible responses to thermal and mechanical stimuli. The xerogel is a highly efficient (0.005mol% Pd) heterogeneous catalyst for Suzuki-Miyaura couplings with arylhalides and phenylboronic acids in excellent yield in water or ethanol under ambient atmosphere. The reaction could be scaled up to 10gram scale with 0.001mol% Pd catalyst loading with 99% yield. The catalyst can be recycled and reused at least seven times without loss of activity.

Palladium(II) complex of an organotellurium ligand as a catalyst for Suzuki Miyaura coupling: Generation and role of nano-sized Pd3Te2

Organotellurium ligand (L = (C6H5)(2-HOC6H4)CHNH(CH2)3Te–C6H4−4−OMe) and its palladium complex [PdCl(L−H)](1) have been synthesized and characterized by multinuclei NMR and mass spectra. The L coordinates with Pd(II) in a (N,Te,C−) mode. The complex 1 has been used to catalyze Suzuki–Miyaura coupling (SMC) reaction. The conversions at 0.1 mol% loading of the complex catalyst were good for coupling of phenylboronic acid with various aryl bromides. In case of 4-formylphenylboronic acid catalyst loading needed was higher. In the course of catalysis nanoparticles (NPs) were generated. They were isolated and characterized as Pd3Te2 species (∼1−2 nm size). Catalytic activity of 1 has been ascribed via these NPs. A cocktail process involving both homogeneous and heterogeneous routes appears to carry out catalysis.

Pd Immobilized in Mesoporous Silica Particles as Recyclable Catalysts for Suzuki-Miyaura Coupling: Cooperative Effects Exerted by Co-Immobilized Amine Functionalities

A bifunctional heterogeneous palladium catalyst bearing additional basic sites was successfully prepared by sequential Cu-catalyzed 1,3-dipolar alkyne–azide cycloaddition and thermal nitroxide-exchange reaction of surface-bound alkoxyamines. This catalyst shows high activity in the Suzuki–Miyaura cross-coupling. The additional basic functionality acts cooperatively since an analogous heterogeneous Pd catalyst lacking the amine functionality is less active. Such catalysts can be recycled up to ten times without loss of activity.

ChemInform Abstract: Neutral Palladium(II) Complexes with P,N Schiff‐Base Ligands: Synthesis, Characterization and Application as Suzuki—Miyaura Coupling Catalysts.

AbstractPalladium(II) complexes with P,N‐bidentate Schiff base ligands are prepared and tested in Suzuki—Miyaura cross coupling reactions.