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The paper describes the synthesis of a novel nano-sized phosphine-free benzothiazole-based palladium(II) complexes from easily accessible starting materials and study their efficiency as catalysts for Suzuki Miyaura cross coupling reaction using water as a solvent under microwaves irradiations. Structural elucidation of the novel nano-sized benzthiazole-based complexes was achieved by analytical and physical characterization tools. The catalytic activity of the novel nanocatalysts was invetigated for SMC of aryl halides with arylboronic acids using water as a solvent and under microwaves irradiation conditions as green mild reaction conditions. [ABSTRACT FROM AUTHOR]

Heat-up and hot-injection methods were employed to synthesize Ni nanoparticles (NPs) with narrow size distribution in the presence of hyperbranched pyridylphenylene polymer (PPP) as a stabilizing agent. It was shown that depending on the synthetic method, Ni NPs were formed either in a cross-linked polymer network or stabilized by a soluble hyperbranched polymer. Ni NPs were characterized by a combination of transmission electron microscopy (TEM), scanning TEM, thermogravimetric analysis, powder X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive X-ray analysis, and magnetic measurements. The architecture of polymer support was found to significantly effect Ni NPs characteristics and behavior. The Ni NPs demonstrated a high catalytic activity in a model Suzuki–Miyaura cross-coupling reaction. No significant drop in activity was observed upon repeated use after magnetic separation in five consecutive catalytic cycles. We believe that hyperbranched PPP can serve as universal platform for the controllable synthesis of Ni NPs, acting as highly active and stable catalysts. [ABSTRACT FROM AUTHOR]

A novel phosphine-free pyrimidine-based palladium(II) complex have been synthesized from easily accessible starting materials and its ability to be a catalyst for cross-coupling reactions namely, Suzuki-Miyaura (SMC) has been investigated. The structure of the new formamidinyl pyrimidine-based complex has been elucidated by using spectroscopic as well as physical characterization techniques. The novel palladium(II) complex showed its applicability as a catalyst for SMC of 2-bromothiophene and 2,5-dibromothiophene with arylboronic acids under conventional and microwaves irradiation conditions. The developed catalytic system exhibited reasonable catalytic activity to obtain 2-aryl and 2,5-diarylthiophene derivatives using mild reaction conditions. [ABSTRACT FROM AUTHOR]

An amide functionlized bidentate NHC-Pd complex was successfully prepared by a facile solvothermal methodology from a bridged bis-benzimidazolium chloride and K 2 PdCl 4. The new bidentate NHC-Pd complex has been effectively applied as catalyst in Suzuki-Miyaura cross-coupling reactions of aryl halides with arylboronic acids in neat water (yields up to 99.0%). [Display omitted] • A novel bidentate Pd-NHC complex has been synthesized. • The new bidentate Pd-NHC complex showed good activity for Suzuki coupling reaction. • Water was selected as the solvent for Suzuki-Miyaura cross-coupling. • The functional ligand Pd complex is distinctly influenced by the electronic and steric effects on the catalytic process. An amide functionlized bidentate NHC-Pd complex was successfully prepared by a facile solvothermal methodology from a bridged bis-benzimidazolium chloride and K 2 PdCl 4. The new bidentate NHC-Pd complex has been effectively applied as catalyst in Suzuki-Miyaura cross-coupling reactions of aryl halides with arylboronic acids in distilled water (yields up to 99.0%). The bridged bis-benzimidazolium ligand from the Pd complex, bearing the amide functional groups on the nitrogen atom, showed to distinctly influence the electronic and steric effects on the catalytic process. The potential of application of the new NHC-Pd catalyst in diverse C C bond forming processes, working under environmentally friendly conditions, is further outlined. [ABSTRACT FROM AUTHOR]

A straightforward and facile synthesis of cellulosic-carbon-shielded palladium–magnetic nanoparticle hybrid material (Pd-MNP@SCB) is presented here. Naturally abundant cellulose was isolated from waste sugarcane bagasse via simple base hydrolysis method and employed. Large surface area and porosity are crucial factors which can enhance the efficiency of a material in catalysis as well as energy storage application and the same was tried to achieve here using the cellulosic-carbon as a support. The prepared hybrid material was initially screened for its catalytic activity in Suzuki–Miyaura cross-coupling followed by its utilization in energy storage application. Pd-MNP@SCB could catalyze the cross-coupling reaction very efficiently with excellent functional group tolerance and good recyclability. The electrochemical performance was explored for Pd-MNP@SCB assembled in a two-electrode cell configuration. The maximum capacitance was found to be 121.74 F/g at a current density of 0.07 A/g with an excellent cycling stability of 97.69% over 3000 cycles. [ABSTRACT FROM AUTHOR]

In the asymmetric unit, equalling the unit cell (triclinic, P1, Z = 1), two molecules of the title compound, 8-(4-methylphenyl)-d-2′-deoxyadenosine, C17H19N5O3, are present, with distinct conformations of the two sugar moieties, together with one solvent water molecule. All three ribose O atoms are involved in hydrogen bonding and the crystal packing is largely determined by hydrogen-bonding or hydrogen–heteroatom interactions (O—H...O, O—H...N, N—H...O, C—H...O and C—H...N) with one independent molecule directly linked to four neighbouring molecules and the other molecule directly linked to six neighbouring molecules. The two independent molecules of the asymmetric unit display three weak intramolecular C—H-to-heteroatom contacts, two of which are very similar despite the different conformations of the deoxyribosyl moieties. The aromatic ring systems of both molecules are in proximity to each other and somehow aligned, though not coplanar. The absolute structures of the two molecules were assumed with reference to the reactant 8-bromo-d-2′-deoxyadenosine as they could not be determined crystallographically.

The molecule of the title compound, C21H18N2O6, has a bent rather than a linear conformation supported by three intramolecular C—H...O hydrogen bonds. The packing in the crystal lattice is largely determined by interactions between hydrogen atoms with oxygen atom lone pairs with one molecule interacting with neigbouring molecules via O—H...O, N—H...O and C—H...O hydrogen bonds. The title compound crystallizes in the chiral orthorhombic space group P212121. Its absolute structure could not be determined crystallographically and was assumed with reference to that of the reactant 5-iodo-2′-deoxyuridine.

Graphical abstract Abstract We report the synthesis of Fe-NCN pincer complex as homogenous catalyst and its composite by immobilizing the complex on amino functionalized graphene oxide as a heterogeneous catalyst for Suzuki coupling reactions. Both the complex and the composite were employed in catalyzing the Suzuki-Miyaura cross-coupling reaction between the aryl halide and phenyl boronic acid in acetonitrile solvent media with Cs 2 CO 3 as a base. Effect of substitution over aryl halide was also investigated. Immobilization of the pincer complex had advantageous recovery and reuse of the catalyst as compared to its homogenous analog with no significant decrease in the catalytic efficiency. [ABSTRACT FROM AUTHOR]

Pd(II)‐NNN pincer complexes containing sterically hindered 2‐bromopyridine (sp2 hybridized N donor) as ancillary ligand have been synthesized in order to compare their catalytic efficiency with the reported analogous complexes containing acetonitrile (sp hybridized N donor) ancillary ligand. The complexes have been characterized by analytical and spectroscopic techniques. Single crystal XRD reveals distorted square planar structure of complex 1. These complexes have been investigated as catalysts for the Suzuki‐Miyaura cross‐coupling (SMC) reaction. The scope is extended using various substituted aromatic/aliphatic halides. The activity of the Pd(II)‐NNN pincer complexes bearing bulky 2‐bromopyridine ancillary ligand is not higher compared to that of the complexes with acetonitrile ancillary ligand, which shows superiority of acetonitrile ancillary ligand. Pd(II)‐NNN pincer complexes containing 2‐bromopyridine as ancillary ligand have been synthesized and evaluated for their catalytic activity. The catalytic efficiency of the present complexes was compared with the analogous complexes containing acetonitrile ancillary ligand. [ABSTRACT FROM AUTHOR]

[Display omitted] Four nickel complexes incorporating N,N,N -quinolinyl anilido-imine ligands based on ortho -C 6 H 4 F(CH = NAr) and 8-aminoquinoline, Ni[{2-[ArN = C(H)]C 6 H 4 }N(8-C 9 H 6 N)]Br (Ar = 2,6- i Pr 2 C 6 H 3 (1a), 2,4,6-(CH 3) 3 C 6 H 2 (1b), 4-BrC 6 H 4 (1c)) and Ni[{2-[ArN = C(H)]C 6 H 4 }N(8-C 9 H 6 N)] 2 (Ar = 4-ClC 6 H 4 (1d)) were synthesized and structurally characterized by HR-MS, IR, NMR spectroscopy and X-ray crystallography. These nickel(II) complexes were used in Suzuki-Miyaura coupling and exhibited moderate to excellent catalytic activity with a low catalyst loading of 2.0 mol%. [ABSTRACT FROM AUTHOR]

Abstract This work represents an efficient and unique phosphine-free approach for the polystyrene embedded Schiff-base palladium catalyzed diaryl urea synthesis and Suzuki-Miyaura cross-coupling reaction by reductive carbonylation process. The careful instrumental investigations with FE-SEM, TEM, EDAX, TGA, UV–Vis, FTIR, AAS, and elemental analysis precisely characterized the developed heterogeneous catalyst. Reaction parameters, like catalytic natures, starting materials, reaction environment, and solvent were examined sequentially. The present work has been adequately addressed to account for the generation and characterization of a new polymer bound Pd-catalyst and using it in the synthesis of diaryl ureas and diaryl ketones, with no substantial decay of catalytic activity. Graphical abstract Image 1 Highlights • Polymer anchored Pd(PS-SAL) catalyst uniquely synthesized for impending functioning in carbonylation. • Pd(PS-SAL) catalyzes diaryl urea and diaryl ketone synthesis without stringent conditions. • Diaryl urea compounds have miscellaneous bioactivities and medicinal applications. • Diaryl ketones widely used as natural products, cosmetics, pharmaceuticals and biosynthetic precursors. • Polymer embedded heterogeneous catalyst is reusable up to five reaction cycles. [ABSTRACT FROM AUTHOR]

The aromatic dimers play a significant role in many aspects. Herein, we report a simple palladium-carbon catalyst that is highly effective for the dimerization of brominated aromatic compounds under mild conditions using abundant brominated aromatic compounds, bis(pinacolate)diboron and potassium acetate by a 'one-pot' method. This process, which we believe proceeds via a Suzuki-Miyaura crosscoupling reaction mechanism, allows access to a variety of aromatic compounds under mild reaction conditions and has a good functional group tolerance with moderate to high yields. [ABSTRACT FROM AUTHOR]

The palladium complexes of the Pd-PEPPSI type with N-heterocyclic carbenes of the 1,2,4-triazole series were synthesized in 76—99% yields by the reactions of PdCl2 with 1,4-di- alkyl-1,2,4-triazolium salts in pyridine in the presence of KBr or KI as sources of halide ions and tetrabutylammonium salts as phase-transfer catalysts. The obtained complexes can be used as efficient catalysts for the Suzuki—Miyaura cross-coupling and are not inferior to the commercially available Pd-PEPPSI catalysts in activity. [ABSTRACT FROM AUTHOR]

In the asymmetric unit, equalling the unit cell (triclinic, P1, Z= 1), two molecules of the title compound, 8-(4-methylphenyl)-d-20-deoxyadenosine, C17H19N5 O3, are present, with distinct conformations of the two sugar moieties, together with one solvent water molecule. All three ribose O atoms are involved in hydrogen bonding and the crystal packing is largely determined by hydrogen-bonding or hydrogen-heteroatom interactions (O-H…O, O-H…N, N-H…O, C-H…O and C-H…N) with one independent molecule directly linked to four neighbouring molecules and the other molecule directly linked to six neighbouring molecules. The two independent molecules of the asymmetric unit display three weak intramolecular C-H-to-heteroatom contacts, two of which are very similar despite the different conformations of the deoxyribosyl moieties. The aromatic ring systems of both molecules are in proximity to each other and somehow aligned, though not coplanar. The absolute structures of the two molecules were assumed with reference to the reactant 8-bromo-d-2--deoxyadenosine as they could not be determined crystallographically. [ABSTRACT FROM AUTHOR]

The molecule of the title compound, C21H18N2O6, has a bent rather than a linear conformation supported by three intramolecular C--H⋯O hydrogen bonds. The packing in the crystal lattice is largely determined by interactions between hydrogen atoms with oxygen atom lone pairs with one molecule interacting with neigbouring molecules via O--H⋯O, N--H⋯O and C--H⋯O hydrogen bonds. The title compound crystallizes in the chiral orthorhombic space group P212121. Its absolute structure could not be determined crystallographically and was assumed with reference to that of the reactant 5-iodo-2'-deoxyuridine. [ABSTRACT FROM AUTHOR]

A cationic palladium(II) complex, [1,3-bis( N -methylpyridinium-2-ylmethyl)imidazolin-2-ylidene] palladium(II) triiodide ( 3 ), was synthesized from the imidazolium salt 1,3-bis( N -methylpyridinium-2-ylmethyl)imidazolium triiodide ( 2 ) and characterized by 1 H and 13 C{ 1 H} NMR spectroscopy, elemental analysis, and X-ray crystallography. X-ray crystallography revealed that the pyridinium substituted N -heterocyclic carbene ligand exhibits very low steric bulk based on calculated % V bur values. Catalytic application of 3 was tested via the Suzuki–Miyaura cross-coupling of aryl halides with phenylboronic acid in aqueous solutions. Catalytic results suggest 3 catalyzes boronic acid homocoupling while palladium nanoparticles are likely responsible for the observed cross-coupling. [ABSTRACT FROM AUTHOR]

A series of novel N -heterocyclic carbene-palladium(II) complexes 3 were conveniently prepared from commercially available imidazolium salts, palladium chloride, and benzoxazole or benzothiazole in one step. All of the new complexes have been fully characterized by elemental analysis, 1 H, 13 C NMR, and IR spectra. In addition, the molecular structures of complexes 3a-d have also been determined by X-ray single-crystal diffraction. The obtained palladium(II) catalysts showed efficient catalytic activity toward the Suzuki–Miyaura coupling of aryl as well as benzyl chlorides with arylboronic acids. Under the optimal reaction conditions, the expected biaryl products were obtained in moderate to high yields. [ABSTRACT FROM AUTHOR]

In this account the authors' latest results in C-C coupling catalysis are reviewed. First, an efficient catalytic system for the Kumada-Tamao-Corriu coupling reaction based on NHC-phosphine (NHC = N-heterocyclic carbene) nickel complexes is presented. Then the use of palladium complexes of chiral ferrocenyl NHC-phosphines in the asymmetric Suzuki-Miyaura coupling reaction is reported. High catalytic activities and moderate enantioselectivities (ee up to 46%) were obtained. Chiral ferrocenyl phosphine-ethers were also tested in the asymmetric Suzuki-Miyaura reaction yielding good activities and moderate enantioselectivities (ee up to 37%). Finally, the original synthesis of a ferrocenyl rhodium(III) complex and its successful use as catalyst for a C-C coupling reaction via C-H activation of 2-phenylpyridine is presented. [ABSTRACT FROM AUTHOR]

A palladium(II) complex with a known phosphane-free β- d -glucopyranosyl-thiosemicarbazone ligand has been prepared and characterized by spectroscopic studies. The ligand is bonded to the metal in a bidentate coordination mode via the azomethine nitrogen and the thiolate sulfur in the dimeric form. The application of this complex on the Suzuki–Miyaura coupling of aryl bromides with phenylboronic acid in DMF/K 2 CO 3 at 100 °C for 24 h in air, using 0.1 mol% of palladium, afforded the corresponding biaryls in 54–91% yield. Crabtree’s test provided evidence that the real catalyst is mainly heterogeneous rather than homogeneous. [ABSTRACT FROM AUTHOR]

Abstract: A new series of calix[4]arene supported N-heterocyclic carbene palladium complexes were developed and fully characterized. A mono-substituted calix[4]arene was prepared through conventional procedures, following with the attachment of imidazolyl derivative groups to compose the precursors of novel NHCs ligands. Undergoing the alkylation with n-butylbromide and corresponding metallation with palladium and pyridine, original complexes were obtained. After a full characterization in solution and solid state, the evaluation of catalytic activity was taken out in Suzuki–Miyaura cross-coupling reactions, which revealed good performances. [Copyright &y& Elsevier]

Abstract: Pd nanoparticles have been successfully supported on nanoscale metal-organic frameworks (NMOFs) by using a simple and effective microwave-assisted impregnation process. The resulting composite, representing as a highly active NMOFs supported metal nanoparticles catalyst for the Suzuki cross-coupling reaction between aryl/heteroaryl halides and arylboronic acids, is well characterized, and its high activity and good recyclability are discussed in details. It reveals that, compared to the corresponding bulk MOFs and conventional active carbon materials, nanoscale MOFs as novel support materials for heterogeneous catalysts can exhibit superior performance in the catalytic reactions. [Copyright &y& Elsevier]

Abstract: Conditions for one-pot Suzuki–Miyaura cross-coupling between aryl boronic acids and bromo-nitrobenzene followed by reductive monoalkylation of the nitro functionality of the biaryl cross-coupling product utilizing hydrogen over Pd/C as the catalyst and aldehydes as alkylation agent are described. [Copyright &y& Elsevier]

Monodisperse Ni/Pd core/shell nanoparticles (NPs) have been synthesized by sequential reduction of nickel(II) acetate and palladium(II) bromide in oleylamine (OAm) and trioctylphosphine (TOP). The Ni/Pd NPs have a narrow size distribution with a mean particle size of 10 nm and a standard deviation of 5% with respect to the particle diameter. Mechanistic studies showed that the presence of TOP was essential to control the reductive decomposition of Ni-TOP and Pd-TOP, and the formation of Ni/Pd core/shell NPs. Using the current synthetic protocol, the composition of the Ni/Pd within the core/shell structure can be readily tuned by simply controlling the initial molar ratio of the Ni and Pd salts. The as-synthesized Ni/Pd core/shell NPs were supported on graphene (G) and used as catalyst in Suzuki-Miyaura cross-coupling reactions. Among three different kinds of Ni/Pd NPs tested, the Ni/Pd (Ni/Pd = 3/2) NPs were found to be the most active catalyst for the Suzuki-Miyaura cross-coupling of arylboronic acids with aryl iodides, bromides and even chlorides in a dimethylformamide/water mixture by using KCO as a base at 110 °C. The G-Ni/Pd was also stable and reusable, providing 98% conversion after the 5 catalytic run without showing any noticeable Ni/Pd composition change. The G-Ni/Pd structure reported in this paper combines both the efficiency of a homogeneous catalyst and the durability of a heterogeneous catalyst, and is promising catalyst candidate for various Pd-based catalytic applications. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The reactivity of a number of chloroarenes was investigated and chloro-nitroarenes were found to undergo facile arylation with Pd(PPh3)4/[Pd(PPh3)2Cl2/n·PPh3] as catalyst. Furthermore, 4-chlorobenzaldehyde underwent arylation under the conditions, albeit with a higher catalyst loading. [ABSTRACT FROM AUTHOR]

Abstract: Ligand-free, palladium-supported, poly(N-isopropylacrylamide-co-potassium methacrylate) [poly(NIPA-co-PMA)] hydrogel nanocomposite with different comonomer ratios were synthesized. The developed hydrogel–palladium composites were characterized by SEM, TEM, UV–vis DRS and XRD. The catalytic performance of these hydrogel–palladium nanocomposites was examined for Suzuki–Miyaura cross-coupling reaction of aryl halides with arylboronic acids in an aqueous medium. The hydrogel with comonomer ratio of 8.8:1.6mmol of NIPA:PMA exhibited optimum catalytic activity, which can be effectively reused 5–6 times without loss of catalytic activity. [Copyright &y& Elsevier]

Abstract: Iridium-catalyzed borylation has been applied to various substituted thiophenes to synthesize poly-functionalized thiophenes in good to excellent yields. Apart from common functionalities compatible with iridium-catalyzed borylations, additional functional group tolerance to acyl (COMe) and trimethylsilyl (TMS) groups was also observed. High regioselectivities were observed in borylation of 3- and 2,5-di-substituted thiophenes. Electrophilic aromatic C–H/C–Si bromination on thiophene boronate esters is shown to take place without breaking the C–B bond, and one-pot C–H borylation/Suzuki–Miyaura cross-coupling has been accomplished on 2- and 3-borylated thiophenes. [Copyright &y& Elsevier]

Abstract: Thiosemicarbazone-derivatised palladium nanoparticles with average crystallite size 16.2nm have been prepared and characterized by XRD and SEM. The nanoparticles were found to efficiently catalyze the Suzuki–Miyaura cross-coupling of aryl bromides (from electron-rich to electron poor) with phenylboronic acid even at room temperature, and they can be recovered and reused. [Copyright &y& Elsevier]

The construction of a high stability heterogeneous catalyst for privileged common catalysis is a benefit in regard to reuse and separation. Herein, a palladium diphenylphosphine-based hollow-shell-structured mesoporous catalyst (HS@PdPPh2@MSN) was prepared by immobilizing bis((diphenylphosphino)ethyltriethoxysilane)palladium acetate onto the inner wall of a mesoporous organicsilicane hollow shell, whose surface was protected by a –Si(Me)3 group. Electron microscopies confirmed its hollow-shell-structure, and structural analyses and characterizations revealed its well-defined single-site active species within the silicate network. As presented in this study, the newly constructed HS@PdPPh2@MSN enabled an efficient Suzuki-Miyaura cross-coupling reaction for varieties of substrates with up to 95% yield in mild conditions. Meanwhile, it could be reused at least five times with good activity, indicating its excellent stability and recyclability. Furthermore, the cost-effective and easily synthesized HS@PdPPh2@MSN made it a good candidate for employment in fine chemical engineering. [ABSTRACT FROM AUTHOR]