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Suzuki
Kinds of Suzuki Terms modified by Suzuki Selected AbstractsTandem Stille/Suzuki,Miyaura Coupling of a Hetero-Bis-Metalated Diene.CHEMINFORM, Issue 42 2005One-Pot Assembly of Polyene Systems., Rapid Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis and Characterisation of (Alkoxybenzimidazolin-2-ylidene)palladium Complexes: The Effect of Ancillary Ligands on the Behaviour of PrecatalystsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 13 2009Murray V. Baker Abstract A series of new N-heterocyclic carbene (NHC),palladium(II) complexes bearing electron-rich benzimidazolin-2-ylidene ligands are described and structurally and spectroscopically characterised. These (benzimidazolin-2-ylidene)palladium complexes bear butoxy groups to increase the solubility and perhaps influence the catalytic activity by increasing the electron density around the metal centre. The effect of varying the ancillary ligands is investigated, although these ligands do not appear to significantly alter the activity of the complexes as precatalysts. Preliminary studies indicate the complexes act as precatalysts with moderate activity in the Mizoroki,Heck and Suzuki,Miyaura coupling reactions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Impairment of eyeblink conditioning in GluR,2-mutant mice depends on the temporal overlap between conditioned and unconditioned stimuliEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2001Yasushi Kishimoto Abstract Mice lacking the glutamate receptor subunit ,2 (GluR,2) are deficient in cerebellar long-term depression (LTD) at the parallel fibre,Purkinje cell synapses. We conducted delay and trace eyeblink conditioning with these mice, using various temporal intervals between the conditioned stimulus (CS) and unconditioned stimulus (US). During trace conditioning in which a stimulus-free trace interval (TI) of 250, 100 or 50 ms intervened between the 352-ms tone CS and 100-ms US, GluR,2-mutant mice learned as successfully as wild-type mice. Even in the paradigm with TI = 0 ms, in which the end of CS and onset of US are simultaneous, there was no difference between the GluR,2-mutant and wild-type mice in their acquisition of a conditioned response. However, in the delay paradigm in which the 452-ms CS overlapped temporally with the coterminating 100-ms US, GluR,2-mutant mice exhibited severe learning impairment. The present study together with our previous work [Kishimoto, Y., Kawahara, S., Suzuki, M., Mori, H., Mishina, M. & Kirino, Y. (2001) Eur. J. Neurosci.,13, 1249,1254], indicates that cerebellar LTD-independent learning is possible in paradigms without temporal overlap between the CS and US. On the other hand, GluR,2 and cerebellar LTD are essential for learning when there is CS,US temporal overlap, suggesting that the cerebellar neural substrates underlying eyeblink conditioning may change, depending on the temporal overlap of the CS and US. [source] Selective Tuning of the HOMO,LUMO Gap of Carbazole-Based Donor,Acceptor,Donor Compounds toward Different Emission ColorsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 9 2010Huaqiang Zhang Abstract Carbazole-based donor,acceptor compounds with tunable HOMO,LUMO gaps were synthesized by Suzuki and Sonogashira cross-coupling reactions. Their optical and electrochemical properties were fully characterized. The results show that materials with different emission colors ranging from blue to green to orange could be obtained. The experimental results were also supported by theoretical calculations. [source] Biaryl Peptides from 4-Iodophenylalanine by Solid-Phase Borylation and Suzuki,Miyaura Cross-CouplingEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 8 2010Ana Afonso Abstract Resin-bound phenylalanine boronates were prepared by solid-phase Miyaura borylation of 4-iodophenylalanine peptides. Subsequent arylation through a Suzuki,Miyaura cross-coupling was carried out using a variety of aryl halides under conventional heating and under microwave irradiation. Microwaves greatly enhanced the arylation, shortening thereaction time and providing the biaryl peptides in higherpurities. [source] Polyarylated Thiazoles via a Combined Halogen Dance , Cross-Coupling StrategyEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 19 2009Michael Schnürch Abstract The application of the halogen dance reaction for the synthesis of starting materials for cross-coupling reactions is reported. The obtained compounds were then successfully applied in sequential Stille and Suzuki,Miyaura cross-coupling reactions to obtain novel thiazole derivatives. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Very Fast Suzuki,Miyaura Reaction Catalyzed by Pd(OAc)2 under Aerobic Conditions at Room Temperature in EGME/H2OEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 1 2009Alessandro Del Zotto Abstract The results of a ligand-free Pd(OAc)2 -catalyzed Suzuki,Miyaura C,C coupling performed at room temperature under aerobic conditions are presented. It was found that the use of an ethylene glycol monomethyl ether/H2O mixture as the solvent resulted in very rapid reactions of aryl bromides with arylboronic acids. As a matter of fact, under optimized conditions, some substrates were converted quantitatively in less than 1 min with exceptionally high TOF values. For example, the reaction between 4-methoxyphenylboronic acid and bromobenzene afforded 4-methoxybiphenyl in 30 s with TOF = 180000 h,1. Furthermore, the reaction tolerates a wide range of functional groups and can be successfully applied to heteroaryl bromides such as 2-bromopyridine and 5-bromopyrimidine. Interestingly, also an activated aryl chloride such as 1-chloro-4-nitrobenzene reacted quantitatively with phenylboronic acid at 373 K. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Development of New Pyrrolocoumarin Derivatives with Satisfactory Fluorescent Properties and Notably Large Stokes ShiftsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 36 2008Lei Chen Abstract Small, organic, fluorescent molecules with large Stokes shifts and long emission wavelengths are ideal dyes for various modern fluorescent imaging technologies such as FRET. In this study, we designed and synthesized a number of new fluorescent molecules on the basic structures of two pyrrolocoumarin skeletons where Fischer's indole synthesis and the Suzuki coupling successfully served as the efficient molecular editing protocols. The examination of the fluorescent properties and further structural optimization of these compounds afforded three new pyrrolocoumarin dyes with notably large Stokes shifts and satisfactory fluorescent properties. Among these, 30 showed a large Stokes shift (113 nm) and intense fluorescence (, = 0.55, ,em = 523 nm), and thus showed great potential in biological imaging studies. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Suzuki,Miyaura Coupling Reaction of Boronic Acids and Ethyl Glyoxylate: Synthetic Access to Mandelate DerivativesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 34 2008Irene Notar Francesco Abstract The palladium-catalyzed coupling reaction of arylboronicacids with ethyl glyoxylate provides a straightforward method for the synthesis of mandelic esters. Pd2(dba)3·CHCl3 in combination with 2-di- tert -butylphosphanylbiphenyl as the catalytic system and Cs2CO3 as the base were used. The reaction tolerates a wide range of functionalized boronicacids. Mandelic esters were isolated in good-to-excellent yields with a variety of neutral, slightly electron-rich, and slightly electron-poor substituents.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Three Phase Microemulsion/Sol,Gel System for Aqueous C,C Coupling of Hydrophobic SubstratesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 14 2008Dmitry Tsvelikhovsky Abstract Heck, Stille, Suzuki and three-component coupling reactions with hydrophobic substrates have been carried out in water. The substrates are initially transformed by a general procedure into a microemulsion, which consists of nearly 90,% water with the aid of sodium dodecyl sulfate and either PrOH or BuOH. The surfactant carries the molecules of the substrates to Pd(OAc)2 entrapped within a hydrophobicitized silica sol,gel matrix where the coupling between the substrates is assumed to take place. The products are then returned by the surfactant into the microemulsion from which it can be released. The immobilized palladium catalyst is leach proof and recyclable. It can be used in various coupling processes at least six times without loss of activity. Experiments with D2O have revealed that the water does not take part in the coupling process, but it has an effect on the pore size of the sol,gel matrix, which hosts the palladium catalyst. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] CuI/DABCO-Catalyzed Cross-Coupling Reactions of Aryl Halides with Arylboronic AcidsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 9 2006Jin-Heng Li Abstract CuI combined with DABCO (1,4-diaza-bicyclo[2.2.2]octane) was developed as an inexpensive and efficient catalytic system for the Suzuki,Miyaura cross-coupling of aryl halides with arylboronic acids. The couplings between aryl iodides and arylboronic acids catalyzed by catalytic amounts of CuI and DABCO proceeded smoothly in moderate to excellent yields. However, the CuI/DABCO system was less efficient in the reactions of aryl bromides, and a higher reaction temperature was required to improve the yield. For the less activated aryl bromides, a stoichiometric amount of CuI together with TBAB was necessary to obtain satisfactory yields. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Palladium-Catalyzed Suzuki,Miyaura Cross-Coupling Using Phosphinous Acids and Dialkyl(chloro)phosphane LigandsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 8 2006Christian Wolf Abstract The use of eleven palladium complexes having monomeric and ,-chloro-bridged dimeric structures and either bulky dialkyl- and diarylphosphinous acid ligands (POPd, POPd-Br, POPd1, POPd2, POPd6, POPd7, Ph1-Phoxide) or dialkyl(chloro)phosphane ligands (PXPd, PXPd2, PXPd6, PXPd7) for Suzuki,Miyaura coupling reactions has been evaluated. Screening and optimization of catalyst loading, solvent, temperature, and base showed that excellent results can be obtained with electron-deficient and electron-rich aryl iodides, bromides, and chlorides in the presence of 2.5 mol-% of palladium,phosphinous acid POPd, (tBu2POH)2PdCl2, in 1,4-dioxane using cesium carbonate as base. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Introduction of Aromatic and Heteroaromatic Groups in the 2- and 8-Positions of the Tröger's Base Core by Suzuki, Stille and Negishi Cross-Coupling Reactions , A Comparative StudyEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 16 2005Carlos Solano Abstract A comparative study on the bis(functionalization) of the Tröger's base core by aromatic and heteroaromatic groups using palladium-catalyzed cross-coupling reactions is presented. Three different reactions, the Suzuki, Stille, and Negishi couplings, were investigated using Tröger's base analogues equally substituted in the 2,8-positions with (HO)2B, Bu3Sn and ZnCl groups, respectively, as the metallated component. Six aryl halides with different electronic and steric properties were employed as coupling partners. The presence of the bulky and electron-rich phosphane P(tBu)3 as co-catalyst was found to play an important role. In addition, the palladium source, [Pd(PPh3)4] or [Pd2(dba)3], was also found to be an important factor for the yield of the reactions. The Suzuki coupling was found to be the best method in general, giving excellent yields for most aryl halides, whereas the Stille and Negishi couplings gave moderate to good yields. Finally, the crystal structures of the 4-nitrophenyl- and the 2-pyridyl-appended analogues of Tröger's base, 7d and 7f, are presented in the Supporting Information. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Generation of a Small Library of Highly Electron-Rich 2-(Hetero)Aryl-Substituted Phenethylamines by the Suzuki,Miyaura Reaction: A Short Synthesis of an Apogalanthamine AnalogueEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 15 2004Prasad Appukkuttan Abstract The Suzuki,Miyaura reaction is presented as a versatile procedure for the synthesis of a small library of highly electron-rich 2-[4,5-dimethoxy-2-(hetero)arylphenyl]ethylamines. Microwave-irradiation accelerates the reaction tremendously and furnishes superior yields. The difficult oxidative addition of the catalyst to a highly electron-rich and ortho -substituted system could be performed easily, and the proto-deboronation during cross-coupling reactions involving the highly electron-withdrawing (2-formylphenyl)boronic acid could be minimized. Enhanced yields and complete compatibility with aqueous conditions were found. This strategy was developed en route towards the synthesis of an apogalanthamine analogue. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] An iterative strategy for the synthesis of oligothiophenes by catalytic cross-coupling reactionsHETEROATOM CHEMISTRY, Issue 2 2004Thomas Pinault An iterative strategy for the synthesis of new sulfur-functionalized oligothiophenes by Suzuki or Stille cross-coupling reactions was applied to the reaction of 4-bromo-tert-butylphenylthioether with thiophene derivatives. The planarity of the oligothiophenes obtained was confirmed by the single-crystal X-ray structure analysis of 2-(4,-tert-butylthiophenyl)thiophene, which shows a potentially large electronic conjugation length. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:121,126, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10224 [source] Insoluble Perfluoroalkylated Polymers: New Solid Supports for Supported Fluorous Phase CatalysisADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010Nicolas Audic Abstract New perfluoroalkylated polystyrene resins have been prepared by the suspension polymerisation of 4-(perfluoro- n -octyl)styrene. The evaluation of these highly fluorinated insoluble materials as catalyst supports for rhodium-catalysed hydrogenation of styrene and palladium-mediated Suzuki,Miyaura carbon-carbon bond forming reactions with 4-bromoacetophenone and 4-bromoanisole revealed improvements in the recycling of the perfluoroalkylated catalysts as compared to that achieved using fluorous reverse-phase silica gel. [source] Synthesis of Aryl-Substituted Pyrimidines by Site-Selective Suzuki,Miyura Cross-Coupling Reactions of 2,4,5,6-TetrachloropyrimidineADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2010Munawar Hussain Abstract Suzuki,Miyaura reactions of 2,4,5,6-tetrachloropyrimidine allow a convenient synthesis of mono-, di-, tri- and tetraarylpyrimidines which are not readily available by other methods. All reactions proceed with excellent site-selectivity. [source] Sulfonated N -Heterocyclic Carbenes for Pd-Catalyzed Sonogashira and Suzuki,Miyaura Coupling in Aqueous SolventsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2010Sutapa Roy Abstract The reactions of the N,N, -diarylimidazolium and N,N, -diarylimidazolinium salts with chlorosulfonic acid result in the formation of the respective disulfonated N -heterocyclic carbene (NHC) precursors in reasonable yields (46,77%). Water-soluble palladium catalyst complexes, in situ obtained from the respective sulfonated imidazolinium salt, sodium tetrachloropalladate (Na2PdCl4) and potassium hydroxide (KOH) in water, were successfully applied in the copper-free Sonogashira coupling reaction in isopropyl alcohol/water mixtures using 0.2,mol% catalyst loading. The preformed (disulfonatedNHC)PdCl(cinnamyl) complex was used in aqueous Suzuki,Miyaura reactions at 0.1,mol% catalyst loading. The coupling protocol reported here is very useful for Sonogashira reactions of N - and S -heterocyclic aryl bromides and chlorides with aryl- and alkylacetylenes. [source] The 1,3-Diaminobenzene-Derived Aminophosphine Palladium Pincer Complex {C6H3[NHP(piperidinyl)2]2Pd(Cl)} , A Highly Active Suzuki,Miyaura Catalyst with Excellent Functional Group ToleranceADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2010Jeanne Abstract The rapidly prepared 1,3-diaminobenzene-derived aminophosphine pincer complex {C6H3[NHP(piperidinyl)2]2Pd(Cl)} (1) is an effective Suzuki catalyst with excellent functional group tolerance. Side-product formations, such as homocoupling, debromation or protodeboration have only rarely been detected and if so, were in all cases below the 5% level. The presented reaction protocol is universally applicable. Experimental observations indicate that palladium nanoparticles are the catalytically active form of 1. [source] Retraction: Iron-Catalyzed Suzuki,Miyaura Cross-Coupling ReactionADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2010David Bézier No abstract is available for this article. [source] Palladium(II)-Phosphine Complexes Supported on Magnetic Nanoparticles: Filtration-Free, Recyclable Catalysts for Suzuki,Miyaura Cross-Coupling ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010Sankaranarayanapillai Shylesh Abstract An organic-inorganic hybrid heterogeneous nanocatalyst system was synthesized by covalent grafting a palladium dichloride complex of the type (L)2PdCl2 (L=trimethoxysilyl-functionalized triphenylphosphine) on silica-coated magnetic nanoparticles. It is a highly active and recyclable catalyst for the Suzuki,Miyaura cross-coupling reaction. The new catalyst can easily be separated from the reaction mixture by applying an external magnetic field and can be recycled many times without any loss of activity. [source] Recyclable Heterogeneous Palladium Catalysts in Pure Water: Sustainable Developments in Suzuki, Heck, Sonogashira and Tsuji,Trost ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1 2010Marc Lamblin Abstract This review summarizes the progress made essentially these last ten years on heterogeneous palladium catalysis in pure water. The work covers four important palladium-catalyzed transformations for carbon-carbon bond formation: Suzuki, Heck, Sonogashira and Tsuji,Trost reactions. The discussion focuses on the efficiency and reusability of the heterogeneous catalysts as well as on the experimental conditions from a sustainable chemistry point of view. The review is introduced by a discussion on mechanistic aspects inherent to heterogeneous catalysis. [source] Nine Times Fluoride can be Good for your Syntheses.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009Not just Cheaper: Nonafluorobutanesulfonates as Intermediates for Transition Metal-Catalyzed Reactions Abstract How much fluoride is good for a strong electron-withdrawing effect? In this review we summarize recent results on the use of perfluoroalkanesulfonates, in particular of the cost effective nonafluorobutanesulfonates (nonaflates), in transition metal-catalyzed reactions and a few other typical transformations. During the last decade many advantages over the commonly used triflates have been discovered. The generation of alkenyl and (het)aryl nonaflates and their applications in metal-catalyzed processes such as Heck, Suzuki, Sonogashira, Stille, and Negishi couplings or amination reactions are described. Although far from a systematic investigation, all the presented results clearly demonstrate the many advantages of nonaflates and of similar higher fluorinated sulfonates in laboratory and industrial scale organic synthesis. [source] Review of generative models for the narrowband land mobile satellite propagation channelINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 4 2008F. P. Fontan Abstract The land mobile satellite (LMS) propagation channel is frequently described using statistical models. These models usually make different assumptions regarding the behavior of the direct signal, the diffuse multipath component and the shadowing effects. This paper analyzes the theoretical formulation and implementation of time-series synthesizers based on three typical statistical models: Loo, Corazza,Vatalaro and Suzuki, describing their similarities and differences. The discussion is not limited to the amplitude of the complex envelope but also to the phase variations and Doppler spectra. Finally, guidelines are also provided for comparing model parameters supplied by different authors. Copyright © 2008 John Wiley & Sons, Ltd. [source] Expanded Heterogeneous Suzuki,Miyaura Coupling Reactions of Aryl and Heteroaryl Chlorides under Mild ConditionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009Dong-Hwan Lee Abstract A mesoporous LTA zeolite (MP-LTA)-supported palladium catalyst was developed for the highly efficient Suzuki,Miyaura reaction of aryl and heteroaryl chlorides. The couplings of various aryl chlorides with arylboronic acids in aqueous ethanol were efficiently achieved in the presence of 1.0,mol% of the catalyst. Furthermore, the scope of this catalyst was extended to the coupling of heteroaryl chlorides. Regardless of the substituents, all of the coupling reactions were very clean and highly efficient under mild heating. It shows that our catalyst is one of the most powerful heterogeneous catalysts for the coupling of a wide range of aryl and heteroaryl chlorides. The catalyst could be repetitively used at least 10 times without a significant loss of its catalytic activity. Compared to mesoporous SBA-15 and MCM-41 materials, the MP-LTA support proved to be very stable and robust to prevent degradation upon reuse. [source] Synthesis of 2,3-Diarylbenzo[b]thiophenes via Nickel-Catalyzed Suzuki,Miyaura Cross-Coupling and Palladium-Catalyzed Decarboxylative ArylationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009Mitsuru Miyasaka Abstract We report a new approach to 2,3-diarylbenzo[b]thiophenes based on the nickel-catalyzed Suzuki,Miyaura cross-coupling/palladium-catalyzed decarboxylative arylation sequence of 3-chloro-2-methoxycarbonylbenzo[b]thiophenes, which are readily accessible from the corresponding cinnamic acids. In addition, this methodology can be applied to the concise synthesis of ,-extended 2,3,6,7-tetraarylbenzo[1,2- b;4,5- b,]dithiophenes. Their optical properties are also described. [source] Hydroxypropyl-,-Cyclodextrin-Capped Palladium Nanoparticles: Active Scaffolds for Efficient Carbon-Carbon Bond Forming Cross-Couplings in WaterADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009Jaqueline Abstract A new approach for the preparation of palladium nanoparticles in water from a renewable source, 2-hydroxypropyl-,-cyclodextrin (,-HPCD), which acts both as a reductant and capping agent, is presented. The palladium nanoparticles were characterized by using dynamic light scattering (DLS), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), which revealed the formation of spherical particles in the size range of 2,7,nm. Further analysis by Fourier-transform infrared spectroscopy (FT-IR) and 1H,NMR did not show covalent bonds between cyclodextrins and palladium nanoparticles, suggesting that ,-HPCD is only physically adsorbed on the nanoparticle surface, presumably through hydrophobic interactions which limit the mutual coalescence of nanoclusters. The catalytic activity was tested in Suzuki, Heck and Sonogashira reactions in neat water, providing good yields and selectivities of coupling products under very low Pd loadings (0.5,0.01,mol%). Remarkably, the nanocatalyst showed significant stability hence the aqueous phase remained active for four subsequent runs. The combination of a binding site for substrates (the HPCD cavity) and a reactive centre (Pd core) provides a potential to explore functional catalysis in aqueous medium. [source] Insights into the Role of New Palladium Pincer Complexes as Robust and Recyclable Precatalysts for Suzuki,Miyaura Couplings in Neat WaterADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2009Blanca Inés Abstract Suzuki,Miyaura biaryl and diarylmethane syntheses via the coupling of arylboronic acids with aryl and arylmethyl bromides are performed in water by means of two new CNC-type palladium pincer complexes. Good to excellent results (including high TON values and extended recycling procedures) are obtained in most cases for a range of electronically dissimilar halides and boronic acids. On the basis of a series of kinetics studies, transmission electron microscopy (TEM), mercury drop tests, and quantitative poisoning experiments, the real role of the latter palladacycles, closely linked to the formation and active participation of palladium nanoparticles, is discussed. [source] "Click" Polymer-Supported Palladium Nanoparticles as Highly Efficient Catalysts for Olefin Hydrogenation and Suzuki Coupling Reactions under Ambient ConditionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2009Cátia Ornelas Abstract Complexation of palladium(II) acetate [Pd(OAc)2] or dipotassium tetrachloropalladate [K2PdCl4] to "click" polymers functionalized with phenyl, ferrocenyl and sodium sulfonate groups gave polymeric palladium(II)-triazolyl complexes that were reduced to "click" polymer-stabilized palladium nanoparticles (PdNPs). Transmission electron microscopy (TEM) showed that reduction using sodium borohydride (NaBH4) produced PdNPs in the 1,3,nm range of diameters depending on the nature of the functional group, whereas slow reduction using methanol yielded PdNPs in the 22,25,nm range. The most active of these PdNPs (0.01% mol Pd), stabilized by poly(ferrocenyltriazolylmethyl)styrene, catalyzed the hydrogenation of styrene at 25,°C and 1 atm hydrogen, with turnover numbers (TONs) of 200,000. When stabilized by the water-soluble poly(sodium sulfonate-triazolylmethyl)styrene, the PdNPs (0.01% mol Pd) catalyze the Suzuki,Miyaura coupling between iodobenzene (PhI) and phenylboronic acid [PhB(OH)2] in water/ethanol (H2O/EtOH) at 25,°C with TONs of 8,200. This high catalytic activity is comparable to that obtained with "click" dendrimer-stabilized PdNPs under ambient conditions. [source] Retraction: Iron-Catalyzed Suzuki,Miyaura Cross-Coupling ReactionADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009David Bézier Abstract The following article from Advanced Synthesis & Catalysis, "Iron-Catalyzed Suzuki-Miyaura Cross-Coupling Reaction" by David Bézier and Christophe Darcel, published online on July 27, 2009, in Wiley InterScience (www.interscience.wiley.com), and in print in Volume 351, Issue 11+12, 2009, pages 1732,1736, has been retracted by agreement between the authors, the journal Editor, Joe P. Richmond, and Wiley-VCH Verlag GmbH & Co. KGaA. The retraction has been agreed due to the following. [source] | ||||||||||||||||||||||||||||