Rhodium complexes containing chiral P-donor ligands as catalysts for asymmetric hydrogenation in non conventional media

Escárcega‐Bobadilla, Martha V.; Rodríguez‐Pérez, Laura; Teuma, Emmanuelle; Serp, Philippe; Masdeu‐Bultó, Anna M.; Gómez, Montserrat

doi:10.1007/s10562-011-0568-4

Cited by 15 publications

(9 citation statements)

References 37 publications

(40 reference statements)

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“…[49] Gomez and co-workersc ompared ifferent reactionm edia such as organic solvent (CH 2 Cl 2 ), ionic liquid ([Bmim][PF 6 ]), supercritical carbon dioxide (scCO 2 ), and a [Bmim][PF 6 ]/scCO 2 mixture in the rhodium-catalyzed asymmetric hydrogenation of prochiral olefins by using P-donorl igands with a1 ,1'-bi-2-naphthol (BINOL) backbone. [50] The best enantioselectivity is observed in neat [Bmim][PF 6 ]; however,u pon recycling the catalyst in this system, the enantioselectivity decreasesa saresult of ligand leaching. To improvet he recycling of the catalyst, the ionic liquid phase containing the rhodium speciesc an be immobilizedo nf unctionalized multiwalled carbon nanotubes.…”

Section: Enantioselective Hydrogenationmentioning

confidence: 99%

Ionic Liquids in Asymmetric Synthesis: An Overall View from Reaction Media to Supported Ionic Liquid Catalysis

et al. 2018

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Ionic liquids, as a special class of organic compounds, have attracted ever‐growing interest in recent years. They have been employed in many organic transformations as a green alternative to volatile organic solvents and as a catalyst to modify catalytic activity and recyclability. Recent developments have demonstrated that ionic liquids might also have many benefits in asymmetric reactions. In this review, we survey the use of ionic liquids in asymmetric transformations, including the use of ionic liquids as reaction media in asymmetric reactions, ionic‐liquid‐tagged chiral catalysts for use in asymmetric synthesis, and supported ionic liquid catalysts in asymmetric transformations.

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Section: Enantioselective Hydrogenationmentioning

confidence: 99%

Ionic Liquids in Asymmetric Synthesis: An Overall View from Reaction Media to Supported Ionic Liquid Catalysis

et al. 2018

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“…These properties are mainly originated by their low-dimensionality (1D, 2D) and high surface-to-volume ratio as well as their π-conjugated surface [8], which have propelled their incorporation into a wide range of functional systems where they usually play a central role. The usage of these nanostructures commonly takes advantage of one or more of the Nanomaterials 2020, 10, 614 2 of 13 different properties they possess, for instance, as nanometric supports for heterogeneous catalysts [9][10][11], optical or electrochemical transducers in sensors and biosensors [12][13][14][15], mechanical reinforcement or electrical percolation modulation in polymer nanocomposites [16][17][18][19][20], nanoscale-enhanced radiosensitization and drug delivery in cancer therapy and tumor bioimaging [21][22][23], among others. However, in order to provide them with the additional features required for a particular purpose (catalytic activity, ion recognition, stimuli responsiveness, etc.…”

Section: Introductionmentioning

confidence: 99%

Control of pH-Responsiveness in Graphene Oxide Grafted with Poly-DEAEMA via Tailored Functionalization

et al. 2020

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Polymer-grafted nanomaterials based on carbon allotropes and their derivatives (graphene oxide (GO), etc.) are typically prepared by successive reaction stages that depend upon the initial functionalities in the nanostructure and the polymerization type needed for grafting. However, due to the multiple variables involved in the functionalization steps, it is commonly difficult to predict the properties in the final product and to correlate the material history with its final performance. In this work, we explored the steps needed to graft the carboxylic acid moieties in GO (COOH@GO) with a pH-sensitive polymer, poly[2-(diethylamino)ethyl methacrylate] (poly[DEAEMA]), varying the reactant ratios at each stage prior to polymerization. We studied the combinatorial relationship between these variables and the behavior of the novel grafted material GO-g-poly[DEAEMA], in terms of swelling ratio vs. pH (%Q) in solid specimens and potentiometric response vs. Log[H+] in a solid-state sensor format. We first introduced N-hydroxysuccinimide (NHS)-ester moieties at the –COOH groups (GO-g-NHS) by a classical activation with N-ethyl-N′-(3-dimethylaminopropyl)carbodiimide (EDC). Then, we substituted the NHS-ester groups by polymerizable amide-linked acrylic moieties using 2-aminoethyl methacrylate (AEMA) at different ratios to finally introduce the polymer chains via radical polymerization in an excess of DEAEMA monomer. We found correlated trends in swelling pH range, interval of maximum and minimum swelling values, response in potentiometry and potentiometric linear range vs. Log[H+] and could establish their relationship with the combinatorial stoichiometries in synthetic stages.

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“…Since the discovery of single-walled carbon nanotubes (SWCNTs), 1,2 the scientific communities have applied their outstanding electrical, mechanical and thermal properties 3 in a wide range of cutting-edge applications by modulating their surface properties via covalent 4 and noncovalent 5 strategies. Examples of those applications include their use as transducers in sensors, 6,7 electrodes in solar cells, 8 heterogeneous supports in catalysis, 9 nanoreactors in synthesis, 10 anti-fouling agents in protective films, 11 fillers in composite materials, 12 etc. However, the possibility to modulate the surface properties of their more robust, yet industrially available multiwalled counterparts namely, MWCNTs, to control the directionality in their non-covalent interactions at the nanoscale, has remained a difficult task so far.…”

Section: Introductionmentioning

confidence: 99%

Grafting Multiwalled Carbon Nanotubes with Polystyrene to Enable Self-Assembly and Anisotropic Patchiness

Arenas-García

Escárcega‐Bobadilla

Zelada‐Guillén

2018

JoVE

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We demonstrate a straightforward protocol to graft pristine multiwalled carbon nanotubes (MWCNTs) with polystyrene (PS) chains at the sidewalls through a free-radical polymerization strategy to enable the modulation of the nanotube surface properties and produce supramolecular self-assembly of the nanostructures. First, a selective hydroxylation of the pristine nanotubes through a biphasic catalytically mediated oxidation reaction creates superficially distributed reactive sites at the sidewalls. The latter reactive sites are subsequently modified with methacrylic moieties using a silylated methacrylic precursor to create polymerizable sites. Those polymerizable groups can address further polymerization of styrene to produce a hybrid nanomaterial containing PS chains grafted to the nanotube sidewalls. The polymer-graft content, amount of silylated methacrylic moieties introduced and hydroxylation modification of the nanotubes are identified and quantified by Thermogravimetric Analysis (TGA). The presence of reactive functional groups hydroxyl and silylated methacrylate are confirmed by Fourier Transform Infrared Spectroscopy (FT-IR). Polystyrene-grafted carbon nanotube solutions in tetrahydrofuran (THF) provide wall-to-wall collinearly self-assembled nanotubes when cast samples are analyzed by transmission electron microscopy (TEM). Those self-assemblies are not obtained when suitable blanks are similarly cast from analogous solutions containing non-grafted counterparts. Therefore, this method enables the modification of the nanotube anisotropic patchiness at the sidewalls which results into spontaneous auto-organization at the nanoscale.

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Rhodium complexes containing chiral P-donor ligands as catalysts for asymmetric hydrogenation in non conventional media

Cited by 15 publications

References 37 publications

Ionic Liquids in Asymmetric Synthesis: An Overall View from Reaction Media to Supported Ionic Liquid Catalysis

Ionic Liquids in Asymmetric Synthesis: An Overall View from Reaction Media to Supported Ionic Liquid Catalysis

Control of pH-Responsiveness in Graphene Oxide Grafted with Poly-DEAEMA via Tailored Functionalization

Grafting Multiwalled Carbon Nanotubes with Polystyrene to Enable Self-Assembly and Anisotropic Patchiness

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