Supported Ionic Liquid Phase (SILP) Allylic Alkylation of Amines in Continuous Flow
Ontology highlight
ABSTRACT:
SUBMITTER: Stagel K
PROVIDER: S-EPMC10947303 | biostudies-literature | 2023 May
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Rhodium nanoparticles (NPs) immobilized on imidazolium-based supported ionic liquid phases (Rh@SILP) act as effective catalysts for the hydrogenation of biomass-derived furfuralacetone. The structure of ionic liquid-type (IL) molecular modifiers was systematically varied regarding spacer, side chain, and anion to assess the influence on the NP synthesis and their catalytic properties. Well-dispersed Rh NPs with diameters in the range of 0.6-2.0 nm were formed on all SILP materials, whereby the actual size was dependent significantly on the IL structure. The resulting variations in catalytic activity for hydrogenation of the C=O moiety in furfuralacetone allowed control of the product selectivity to obtain either the saturated alcohol or the ketone in high yield. Experiments conducted under batch and continuous flow conditions demonstrated that Rh NPs immobilized on SILPs with suitable IL structures are more active and much more stable than Rh@SiO2 catalyst synthesized on unmodified silica.
| S-EPMC7737233 | biostudies-literature
Project description:New 1,2,3-triazolium ionic liquid-supported chiral imidazolidinones were developed. The feasibility of the ionic liquid-supported imidazolidinones as chiral auxiliaries was demonstrated in sequential propionylation-alkylation-cleavage reactions, which provided the chiral product with good to excellent chemical yields (up to 90%) and high selectivities (up to 94% ee). The progress of the reactions could be monitored by TLC and NMR, and the ionic liquid-supported chiral auxiliaries could be recovered by simple extraction.
| S-EPMC6766834 | biostudies-literature
Project description:Monolithic silicon carbide supported ionic liquid-phase (SILP) Rh-catalysts have very recently been introduced for gas-phase hydroformylation as an important step toward industrial upscaling. This study investigates the monolithic catalyst system in combination with different impregnation procedures with non-invasive magnetic resonance imaging (MRI). The findings were supported by X-ray microtomography (micro-CT) data of the monolithic pore structure and a catalytic performance test of the catalyst system for 1-butene gas-phase hydroformylation. MRI confirmed a homogeneous impregnation of the liquid phase throughout the full cross-section of the cylindrical monoliths. Consistent impregnations from one side to the other of the monoliths were achieved with a stabilizer in the system that helped preventing inhomogeneous rim formation. External influences relevant for industrial application, such as long-term storage and temperature exposure, did not affect the homogeneous liquid-phase distribution of the catalyst. The work elucidates important parameters to improve liquid-phase catalyst impregnation to obtain efficient monolithic catalysts for industrial exploitation in gas-phase hydroformylation as well as other important industrial processes.
| S-EPMC9053722 | biostudies-literature
Project description:The synthesis of complex oligosaccharides has been a challenge for researchers. Herein, we describe a strategy for the synthesis of an activated oligomannan 1 that employs ionic liquid (IL) support glycosylation methodology on an IL-tagged mannosyl fluoride donor. This method is capable of rapidly producing linear alpha(1-->6) oligomannan thioglycosides in a convenient and cost-effective manner without the need of column purification after each glycosylation step.
| S-EPMC2533115 | biostudies-literature
Project description:A novel method for chemo-enzymatic Baeyer-Villiger oxidation of cyclic ketones in the presence of supported ionic liquid-like phase biocatalyst was designed. In this work, multi-walled carbon nanotubes were applied as a support for ionic liquids which were anchored to nanotubes covalently by amide or imine bonds. Next, lipases B from Candida antarctica, Candida rugosa, or Aspergillus oryzae were immobilized on the prepared materials. The biocatalysts were characterized using various techniques, like thermogravimetry, IR spectroscopy, XPS, elemental analysis, and SEM-EDS microscopy. In the proposed approach, a biocatalyst consisting of a lipase as an active phase allowed the generation of peracid in situ from the corresponding precursor and a green oxidant-hydrogen peroxide. The activity and stability of the obtained biocatalysts in the model oxidation of 2-adamantanone were demonstrated. High conversion of substrate (92%) was achieved under favorable conditions (toluene: n-octanoic acid ratio 1:1 = v:v, 35% aq. H2O2 2 eq., 0.080 g of biocatalyst per 1 mmol of ketone at 20 °C, reaction time 4 h) with four reaction cycles without a drop in its activity. Our 'properties-by-design' approach is distinguished by its short reaction time at low temperature and higher thermal stability in comparison with other biocatalysts presented in the literature reports.
| S-EPMC8269471 | biostudies-literature
Project description:New catalytic materials, based on palladium immobilized in ionic liquid supported on alginate, were elaborated. Alginate was associated with gelatin for the immobilization of ionic liquids (ILs) and the binding of palladium. These catalytic materials were designed in the form of highly porous monoliths (HPMs), in order to be used in a column reactor. The catalytic materials were tested for the hydrogenation of 4-nitroaniline (4-NA) in the presence of formic acid as hydrogen donor. The different parameters for the elaboration of the catalytic materials were studied and their impact analyzed in terms of microstructures, palladium sorption properties and catalytic performances. The characteristics of the biopolymer (proportion of β-D-mannuronic acid (M) and α-L-guluronic acid (G) in the biopolymer defined by the M/G ratio), the concentration of the porogen agent, and the type of coagulating agent significantly influenced catalytic performances. The freezing temperature had a significant impact on structural properties, but hardly affected the catalytic rate. Cellulose fibers were incorporated as mechanical strengthener into the catalytic materials, and allowed to enhance mechanical properties and catalytic efficiency but required increasing the amount of hydrogen donor for catalysis.
| S-EPMC5327881 | biostudies-literature
Project description:The C3-functionalization of furfural using homogeneous ruthenium catalysts requires the preinstallation of an ortho-directing imine group, as well as high temperatures, which did not allow scaling up, at least under batch conditions. In order to design a safer process, we set out to develop a continuous flow process specifically for the C3-alkylation of furfural (Murai reaction). The transposition of a batch process to a continuous flow process is often costly in terms of time and reagents. Therefore, we chose to proceed in two steps: the reaction conditions were first optimized using a laboratory-built pulsed-flow system to save reagents. The optimized conditions in this pulsed-flow mode were then successfully transferred to a continuous flow reactor. In addition, the versatility of this continuous flow device allowed both steps of the reaction to be carried out, namely the formation of the imine directing group and the C3-functionalization with some vinylsilanes and norbonene.
| S-EPMC10167860 | biostudies-literature
Project description:Solvometallurgy is a new branch of extractive metallurgy in which green organic solvents are used instead of aqueous solutions to improve selectivity in separation processes. In the present study, nonaqueous leaching of a Greek bauxite residue (BR) was performed and scandium was separated from other elements in the leachate by column chromatography. At first, the selectivity of sorbents for scandium(III) over iron(III) was tested in batch mode using various organic solvents. The following three sorbents were tested: (1) a carboxylic acid-functionalized supported ionic liquid phase (SILP), (2) silica (SiO2), and (3) silica functionalized with ethylenediaminetetraacetic acid (SiO2-TMS-EDTA). The best separation of scandium and iron was achieved from ethanolic solution by the SILP. The BR was then leached with 0.7 mol L-1 HCl in ethanol or in water. The leaching efficiency of scandium with both lixiviants was similar. However, much less sodium was leached, and silica remained in solution when leaching was performed with the ethanolic lixiviant. By using ethanol as opposed to water, the serious drawback of silica gel formation that is taking place in the aqueous leachate of BR was circumvented. The sorption preference of the SILP for metal ions in the ethanolic leachate was partly reversed compared to the aqueous leachate. Iron was separated from other metals of the ethanolic BR leachate by a simple elution with ethanol. The formation of the anionic tetrachloroferrate(III) complex, [FeCl4]-, enabled the selective elution. This complex was not observed in the aqueous leachate of BR. Scandium was separated from the vast majority of other components of the BR by elution with 0.1 mol L-1 H3PO4.
| S-EPMC7499406 | biostudies-literature
Project description:Amino acid ionic liquid-supported Schiff bases, derivatives of salicylaldehyde and various amino acids (L-threonine, L-valine, L-leucine, L-isoleucine and L-histidine) have been investigated by means of various spectroscopic techniques (NMR, UV-Vis, IR, MS) and deuterium isotope effects on ¹³C-NMR chemical shifts. The results have shown that in all studied amino acid ionic liquid-supported Schiff bases (except the L-histidine derivative) a proton transfer equilibrium exists and the presence of the COO⁻ group stabilizes the proton transferred NH-form.
| S-EPMC6269710 | biostudies-literature
Project description:Hydrogenation of nitriles to primary amines with heterogeneous catalysts under liquid-phase continuous-flow conditions is described. Newly developed polysilane/SiO2-supported Pd was found to be an effective catalyst and various nitriles were converted into primary amine salts in almost quantitative yields under mild reaction conditions. Interestingly, a complex mixture was obtained under batch conditions. Lifetime experiments showed that this catalyst remained active for more than 300 h (TON≥10 000) without loss of selectivity and no metal leaching from the catalyst occurred. By using this continuous-flow hydrogenation, synthesis of venlafaxine, an antidepressant drug, has been accomplished.
| S-EPMC5390790 | biostudies-literature