Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Cage-templated synthesis of highly stable palladium nanoparticles and their catalytic activities in Suzuki-Miyaura coupling.

ABSTRACT: We report the controlled synthesis of small palladium nanoparticles (PdNPs) with narrow particle size distribution (1.8 ± 0.2 nm) using an organic molecular cage as a template. The well-defined cage structure and thioether anchoring groups inside the cavity are critical for the formation of narrowly distributed PdNPs, offering a confined organic molecular environment and guiding PdNP nucleation and growth. The resulting encapsulated PdNPs are resistant to agglomeration and stable in solution exposed to air at room temperature. When provided with a protective cage shell with minimum surface coverage, such PdNPs are capable of catalyzing organic reactions, showing high catalytic activity in Suzuki-Miyaura coupling reactions.

SUBMITTER: Qiu L

PROVIDER: S-EPMC5869600 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Cage-templated synthesis of highly stable palladium nanoparticles and their catalytic activities in Suzuki-Miyaura coupling.

Qiu Li L McCaffrey Ryan R Jin Yinghua Y Gong Yu Y Hu Yiming Y Sun Hongliang H Park Wounjhang W Zhang Wei W

Chemical science 20171109 3

We report the controlled synthesis of small palladium nanoparticles (PdNPs) with narrow particle size distribution (1.8 ± 0.2 nm) using an organic molecular cage as a template. The well-defined cage structure and thioether anchoring groups inside the cavity are critical for the formation of narrowly distributed PdNPs, offering a confined organic molecular environment and guiding PdNP nucleation and growth. The resulting encapsulated PdNPs are resistant to agglomeration and stable in solution exp ...[more]

PMID: 29629135

Similar Datasets

Size-Dependent Catalytic Activity and Fate of Palladium Nanoparticles in Suzuki-Miyaura Coupling Reactions.

Project description:Stable, catalytically active palladium nanoparticles of various average diameters (1.9-7.4 nm) have been synthesized and characterized by X-ray diffraction, spectroscopy, and microscopy techniques to demonstrate remarkable size-dependent and renewed catalytic activity toward the Suzuki-Miyaura coupling reaction in green protocol. The catalytic activity is found to depend on the amount of the reducing agent, stabilizer-precursor ratio, solvent composition, and aryl halides used. The product obtained by this reaction is characterized by 1H NMR, 13C NMR, and IR spectroscopy analyses. A newly developed kinetic equation illustrates that while the catalyst particles of the lowest dimension are gradually exposed to the reactants and hence activated due to partial removal of capping polymer from the catalyst surface, others are deactivated due to agglomeration during the progress of the reaction, as conformed by the microscopic profiles of the used and unused catalysts.

| S-EPMC6645063 | biostudies-literature

Aminophosphine Palladium Pincer-Catalyzed Carbonylative Sonogashira and Suzuki-Miyaura Cross-Coupling with High Catalytic Turnovers.

Project description:This work documents the first palladium pincer complex-catalyzed carbonylative Sonogashira (CS) and carbonylative Suzuki-Miyaura (CSM) cross-coupling. Compared to previous protocols, which employ hazardous and toxic solvents, the aminophosphine pincer complex {[C6H3-2,6-(NHP{piperidinyl}2)2]Pd(Cl)} (III) catalyzes both the cross-coupling reactions in propylene carbonate, an eco-friendly and sustainable polar aprotic solvent. Advantageously, employing III allows the CS cross-coupling to be carried out at a palladium loading of 10-4 mol % and the CSM cross-coupling to be carried out at 10-6 mol %, thus resulting in catalytic turnovers of 105 and 107, respectively. Relative comparison of the pincer complex with conventional palladium precursors Pd(OAc)2 and PdCl2(PPh3)2 shows the efficiency and robustness of the pincer complex in effecting higher catalytic activity at low palladium loadings.

| S-EPMC6648871 | biostudies-literature

Palladium-catalyzed Suzuki-Miyaura coupling of thioureas or thioamides.

Project description:Cross-coupling reactions involving metal carbene intermediates play an increasingly important role in C-C bond formation. Expanding the carbene precursors to a broader range of starting materials and more diverse products is an ongoing challenge in synthetic organic chemistry. Herein, we report a Suzuki-Miyaura coupling reaction of in situ-generated Pd-carbene complexes via desulfurization of thioureas or thioamides. This strategy enables the preparation of a broad array of substituted amidinium salts and unsymmetrical diaryl ketones. The reaction is readily scalable, compatible with bromo groups on aromatic rings, tolerant to moisture and air and has a broad substrate scope. Furthermore, a single crystal structure of Pd-diaminocarbene complex is obtained and proven to be the key intermediate in both catalytic and stoichiometric reactions. Preliminary mechanistic studies demonstrate the dual role of the silver salt as a desulfurating reagent assisting the elimination of sulfur and as oxidant facilitating the PdII/Pd0/PdII catalytic cycle.

| S-EPMC6911099 | biostudies-literature

Palladium complexes containing NNN pincer type ligands and their activities in Suzuki-Miyaura cross coupling reaction.

Project description:Five new NNN pincer-type ligands and their palladium complexes were successfully synthesised and characterised by FT-IR, 1H NMR, 13C NMR, and UV-vis analyses. TEM analysis was used to observe the morphological character of the black residues obtained from the fourth cycle of the reusability test. Furthermore, suitable crystals of the N2,N6-bis(2-tert-butylphenyl)pyridine-2,6-dicarboxamide and its palladium complex were elucidated with the X-ray single crystal diffraction method. Both the ligand and its palladium complex crystallise in a monoclinic system with space group P21/c for the H2L4 and C2/c for the palladium complex. The structure of the pincer ligand and its palladium complex were stabilised by intramolecular and intermolecular C-H⋅⋅⋅O, C-H⋅⋅⋅N, and N-H⋅⋅⋅N contacts. A Suzuki-Miyaura cross-coupling reaction between aryl halides and phenylboronic acid was used to assess the catalytic abilities of the palladium pincer complexes. All of the prepared complexes exhibited considerable catalytic activity. However, complexes 4 (Acetonitrile-N2,N6-bis(2-tert-butylphenyl)pyridine-2,6-dicarboxamidopalladium(II)) and 5 (Acetonitrile-N2,N6-bis(2-nitrophenyl)pyridine-2,6-dicarboxamidopalladium(II)) provided almost 100% conversion with nearly 100% yield in the reaction between 4-bromotoluene and phenylboronic acid. Furthermore, these active complexes catalysed the reaction of the sterically hindered and deactivated substrates (1-Bromo-4-izobutylbenzene and 2-bromo-6-methoxynaphthalene) with phenylboronic acid, and complete conversion and yields up to 100% were achieved in a short time with the 2-bromo-6-methoxynaphthalene.

| S-EPMC10372205 | biostudies-literature

Suzuki-Miyaura Coupling Enabled by Aryl to Vinyl 1,4-Palladium Migration.

Project description:The Suzuki-Miyaura coupling is a fundamentally important transformation in modern organic synthesis. The development of new reaction modes for new chemical accessibility and higher synthetic efficiency is still the consistent pursuance in this field. An efficient Suzuki-Miyaura coupling enabled by a controllable 1,4-palladium migration was realized to afford stereodefined multisubstituted olefins and 1,3-dienes. The reaction exhibits remarkable broad substrate scope, excellent functional-group tolerance, versatile conversion with obtained products, and easy scalability. The practicality of this method is highlighted by the aggregation-induced emission feature of the produced olefins and 1,3-dienes, as well as the capability of affording geometric isomer pairs with a marked difference on photoluminescent quantum yield values.

| S-EPMC7082552 | biostudies-literature

Palladium-scavenging self-assembled hybrid hydrogels - reusable highly-active green catalysts for Suzuki-Miyaura cross-coupling reactions.

Project description:A hybrid hydrogel based on 1,3:2,4-dibenzylidene sorbitol (DBS) modified with acyl hydrazides combined with agarose was used for in situ reduction and binding of palladium from aqueous mixtures without the need for an external reducing agent. Palladium uptake was monitored and the formation of Pd nanoparticles (PdNPs) trapped within the gel and located close to the nanofibres was confirmed. This gel effectively scavenges palladium from solution to concentrations < 0.04 ppm - well below the recommended limits for pharmaceutical products. The resulting hybrid hydrogel with embedded PdNPs was used as a catalyst for Suzuki-Miyaura cross-coupling reactions. The gel network stabilises PdNPs, preventing aggregation/leaching and giving excellent catalytic lifetimes. The gel acts as a simple reaction dosing form, being simply added to reactions performed in green solvents in air. Once reactions are complete, the gel can be simply removed, recycled and reused (>10 times). Reactions were purified by simple washing protocols, and leaching of Pd from the gels is limited (<1 ppm). The gels were also used in flow-through mode, giving efficient, rapid reactions, with easy work-up. These catalytic gels combine advantages of homogeneous and heterogeneous catalysts - they are solvent compatible with the reaction taking place in a solution-like environment, while the solid-like gel network enables catalyst recycling. In summary, these hydrogels scavenge 'waste' palladium and convert it into gel 'wealth' capable of efficient, environmentally-friendly Suzuki-Miyaura catalysis.

| S-EPMC6301269 | biostudies-literature

Enantioselective desymmetrization via carbonyl-directed catalytic asymmetric hydroboration and Suzuki-Miyaura cross-coupling.

Project description:The rhodium-catalyzed enantioselective desymmetrization of symmetric ?,?-unsaturated amides via carbonyl-directed catalytic asymmetric hydroboration (directed CAHB) affords chiral secondary organoboronates with up to 98% ee. The chiral ?-borylated products undergo palladium-catalyzed Suzuki-Miyaura cross-coupling via the trifluoroborate salt with stereoretention.

| S-EPMC4385711 | biostudies-other

Ligand-controlled palladium-catalyzed regiodivergent Suzuki-Miyaura cross-coupling of allylboronates and aryl halides.

Project description:An orthogonal set of catalyst systems has been developed for the Suzuki-Miyaura coupling of 3,3-disubstituted and 3-monosubstituted allylboronates with (hetero)aryl halides. These methods allow for the highly selective preparation of either the ?- or the ?-isomeric coupling product.

| S-EPMC3776608 | biostudies-literature

Synthesis of Biaryls via Decarbonylative Palladium-Catalyzed Suzuki-Miyaura Cross-Coupling of Carboxylic Acids.

Project description:The biaryl motif is a building block in many drugs, agrochemicals, and materials, and as such it is highly desirable as a synthesis target. The state-of-the-art process for biaryl synthesis from ubiquitous carboxylic acids is decarboxylative cross-coupling involving loss of carbon dioxide (CO2). However, the scope of these methods is severely limited, mainly due to specific substitution required to promote decarboxylation. The present report implements a decarbonylative version with loss of carbon monoxide (CO) that enables to directly engage carboxylic acids in a Suzuki-Miyaura cross-coupling to produce biaryls as a general method with high cross-coupling selectivity using a well-defined Pd(0)/(II) catalytic cycle. This protocol shows a remarkably broad scope (>80 examples) and is performed in the absence of exogenous inorganic bases. In a broader context, the approach shows promise for routine applications in the synthesis of biaryls by carefully controlled decarbonylation of prevalent carboxylic acids.

| S-EPMC6731188 | biostudies-literature

Palladium-catalyzed decarbonylative Suzuki-Miyaura cross-coupling of amides by carbon-nitrogen bond activation.

Project description:Palladium-catalyzed Suzuki-Miyaura cross-coupling or aryl halides is widely employed in the synthesis of many important molecules in synthetic chemistry, including pharmaceuticals, polymers and functional materials. Herein, we disclose the first palladium-catalyzed decarbonylative Suzuki-Miyaura cross-coupling of amides for the synthesis of biaryls through the selective activation of the N-C(O) bond of amides. This new method relies on the precise sequence engineering of the catalytic cycle, wherein decarbonylation occurs prior to the transmetallation step. The reaction is compatible with a wide range of boronic acids and amides, providing valuable biaryls in high yields (>60 examples). DFT studies support a mechanism involving oxidative addition, decarbonylation and transmetallation and provide insight into high N-C(O) bond activation selectivity. Most crucially, the reaction establishes the use of palladium catalysis in the biaryl Suzuki-Miyaura cross-coupling of the amide bond and should enable the design of a wide variety of cross-coupling methods in which palladium rivals the traditional biaryl synthesis from aryl halides and pseudohalides.

| S-EPMC6977462 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data