Alternative Solvent Systems in Catalysis

Marset, Xavier; Ramón, Diego J.; Guillena, Gabriela

doi:10.1002/9783527817290.ch6

Cited by 5 publications

(3 citation statements)

References 101 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, these liquids are attractive solvents for the immobilization of organometallic catalysts. [3] For instance, ILs have been successfully employed for various transformations in liquid‐liquid biphasic catalysis, where the formed product segregates from the catalyst solution in an easily separable phase. [4] However, the use of a relatively expensive IL in large quantities may pose economic limitations to the commercialization of an otherwise attractive IL‐based reaction concept.…”

Section: Introductionmentioning

confidence: 99%

Formation and Surface Behavior of Pt and Pd Complexes with Ligand Systems Derived from Nitrile‐functionalized Ionic Liquids Studied by XPS

et al. 2022

View full text Add to dashboard Cite

We studied the formation and surface behavior of Pt(II) and Pd(II) complexes with ligand systems derived from two nitrilefunctionalized ionic liquids (ILs) in solution using angle-resolved X-ray photoelectron spectroscopy (ARXPS). These ligand systems enabled a high solubility of the metal complexes in IL solution. The complexes were prepared by simple ligand substitution under vacuum conditions in defined excess of the coordinating ILs, [C 3 CNC 1 Im][Tf 2 N] and [C 1 CNC 1 Pip][Tf 2 N], to immediately yield solutions of the final products. The ILs differ in the cationic head group and the chain length of the functionalized substituent. Our XPS measurements on the neat ILs gave insights in the electronic properties of the coordinating substituents revealing differences in donation capability and stability of the complexes. Investigations on the composition of the outermost surface layers using ARXPS revealed no surface affinity of the nitrile-functionalized chains in the neat ILs. Solutions of the formed complexes in the nitrile ILs showed homogeneous distribution of the solute at the surface with the heterocyclic moieties preferentially orientated towards the vacuum, while the metal centers are rather located further away from the IL/vacuum interface.

show abstract

Section: Introductionmentioning

confidence: 99%

Formation and Surface Behavior of Pt and Pd Complexes with Ligand Systems Derived from Nitrile‐functionalized Ionic Liquids Studied by XPS

et al. 2022

View full text Add to dashboard Cite

show abstract

“…They typically consist of a quaternary ammonium salt with a metal salt and a hydrogen-bond donor (or acceptor) structure. [44][45][46][47][48] We have developed several interesting synthetic methodologies using DESs during the last decade. [49][50][51] As described below, the DES that we employed showed an appropriate efficiency in the conversion of -nitrostyrenes into -cyanophosphonates with triphenyl phosphite as a nucleophile.…”

Section: Letter Synlettmentioning

confidence: 99%

“…In fact, the reactions were carried out in solvent-free conditions through the Michael addition of triphenyl phosphite to different nitroalkenes. DESs have several [45][46][47][48][49]. In this group, several interesting synthetic methodologies have been developed using DES during the last decade [50][51][52].…”

mentioning

confidence: 99%

Solvent-Free Synthesis of α-Cyanophosphonates from β-Nitrostyrenes using a Deep Eutectic Solvent

Shamsaddinimotlagh,

Ranjbari,

Tavakol

et al. 2024

Synlett

View full text Add to dashboard Cite

New α-Cyanophosphonates, which are useful reagents for Horner-Wittig reaction, were synthesized in a solvent-free condition, using choline chloride-zinc chloride deep eutectic solvent (DES) as a catalyst. This work is only the second report on the synthesis of these compounds. In the previous report, diethyltrimethylsilylphosphite was used as a reagent and TiCl4 as a catalyst while in this study, both employed reagent and catalyst (triphenyl phosphine and choline chloride-zinc chloride DES) are cheaper, more available and less harmful than the previous work. Moreover, the reaction involves an interesting cascade reaction between β-nitrostyrenes and two equivalents of triphenylphosphite led to the desired product as a new synthetic route. These compounds can be used in the pharmaceutical and agricultural industries, in addition to their synthetic applications in the preparation of α,β-unsaturated nitriles. The reactions were completed using 20 mol% of DES at 80 °C in 6 hours. 10 different β-nitrostyrenes were synthesized in 55-87% yield after purification. β-nitrostyrenes containing electron-donating groups showed higher yields. The reaction was failed when aliphatic and heteroaromatic nitroalkenes and β-nitrostyrenes with electron-withdrawing substituent were employed. Finally, three plausible mechanistic routes were proposed for the reaction, starting from the nucleophilic addition of triphenylphosphite to α-carbon, nitrogen and oxygen atoms.

show abstract

Understanding the Buoy Effect of Surface‐Enriched Pt Complexes in Ionic Liquids: A Combined ARXPS and Pendant Drop Study**

Hemmeter,

Paap,

Wellnhofer

et al. 2023

ChemPhysChem

View full text Add to dashboard Cite

Recently, we demonstrated that Pt catalyst complexes dissolved in the ionic liquid (IL) [C4C1Im][PF6] can be deliberately enriched at the IL surface by introducing perfluorinated substituents, which act like buoys dragging the metal complex towards the surface. Herein, we extend our angle‐resolved X‐ray photoelectron spectroscopy (ARXPS) studies at complex concentrations between 30 and 5%mol down to 1%mol and present complementary surface tension pendant drop (PD) measurements under ultra clean vacuum conditions. This combination allows for connecting the microscopic information on the IL/gas interface from ARXPS with the macroscopic property surface tension. The surface enrichment of the Pt complexes is found to be most pronounced at 1%mol. It also displays a strong temperature dependence, which was not observed for 5%mol and above, where the surface is already saturated with the complex. The surface enrichment deduced from ARXPS is also reflected by the pronounced decrease in surface tension with increasing concentration of the catalyst. We furthermore observe by ARXPS and PD a much stronger surface affinity of the buoy‐complex as compared to the free ligands in solution. Our results are highly interesting for an optimum design of ionic catalyst solutions contact areas with a surrounding reactant/product phase, such as in SILP catalysis.

show abstract

Alternative Solvent Systems in Catalysis

Cited by 5 publications

References 101 publications

Formation and Surface Behavior of Pt and Pd Complexes with Ligand Systems Derived from Nitrile‐functionalized Ionic Liquids Studied by XPS

Formation and Surface Behavior of Pt and Pd Complexes with Ligand Systems Derived from Nitrile‐functionalized Ionic Liquids Studied by XPS

Solvent-Free Synthesis of α-Cyanophosphonates from β-Nitrostyrenes using a Deep Eutectic Solvent

Understanding the Buoy Effect of Surface‐Enriched Pt Complexes in Ionic Liquids: A Combined ARXPS and Pendant Drop Study**

Contact Info

Product

Resources

About