Recent Advances in Catalytic Oxidation of Organic Sulfides: Applications of Metal–Ionic Liquid Catalytic Systems

Catalytic oxidation of organic sulfides is of considerable significance in industrial chemistry and fuel industry. Therefore, numerous methods have been developed for the oxidation. Metal-containing ionic liquid-based catalysts can catalyze the selective oxidation reactions and are highly used in chemical processes, which have also been used as effective solvents, reaction media, extractants, and catalysts for the oxidation of organic sulfides including oxidative desulfurization of fuel oil. Recently, much attention is being drawn to the preparation of heterogenous catalysts based on the immobilization of metal- or nonmetal-containing ILs on diverse solid supports, which can be easily separated after the completion reaction and recycled. Therefore, there is still an increasing interest in developing new and efficient catalytic procedures for the oxidation of organic sulfides. In this review, we have outlined the recent advances in catalytic oxidation of organic sulfides including oxidative desulfurization of fuel oil. The versatilities and adaptabilities of metal–ionic liquid catalytic systems in the selective oxidation of sulfides are considered a powerful research field in these transformations.

Automated Multi-Objective Reaction Optimisation: Which Algorithm Should I Use?

Multi-objective optimisation algorithms (MOOAs) are, of increasing interest for the efficient optimisation of chemical processes. However, an algorithms performance can vary on a case-by-case basis, depending on the complexity of...

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

Due to their intrinsic physical properties, which includes being able to perform as volatile liquids at room and biological temperatures, fragrance ingredients/intermediates make ideal candidates for continuous-flow manufacturing. This review highlights the potential crossover between a multibillion dollar industry and the flourishing sub-field of flow chemistry evolving within the discipline of organic synthesis. This is illustrated through selected examples of industrially important transformations specific to the fragrances and flavours industry and by highlighting the advantages of conducting these transformations by using a flow approach. This review is designed to be a compendium of techniques and apparatus already published in the chemical and engineering literature which would constitute a known solution or inspiration for commonly encountered procedures in the manufacture of fragrance and flavour chemicals.

Amphiphilic polymeric nanoreactors containing Rh(i)–NHC complexes for the aqueous biphasic hydrogenation of alkenes

A rhodium(i) complex bearing a monodentate N-heterocyclic carbene ligand has been confined into the core of amphiphilic core-crosslinked micelles (CCMs).

Poly(ionic liquid) composites

This review highlights recent advances in the development of poly(ionic liquid)-based composites for diverse materials applications.

An amphiphilic manganese porphyrin-paired ionic copolymer: a highly efficient biphasic transfer catalyst for the selective oxidation of olefins with O2 and TBHP

A novel amphiphilic manganese porphyrin-paired ionic copolymer, {ADA-INA-[Mn(TPPS)(OAc)]}_n, was prepared by the self-assembly process of non-cross-linked amphiphilic polymeric ligands with inorganic species.

Schiff base complex conjugates of bovine serum albumin as artificial metalloenzymes for eco-friendly enantioselective sulfoxidation

Artificial metalloenzymes (BSA-ML) have been prepared by non-covalent insertion of transition metal Schiff-base complexes, ML (L = 2-hydroxynaphthalen-1-naphthaldehyde and 3,4-diaminobenzenesulfonic acid; M = Co, Mn, V, Fe, Cr), into bovine serum albumin (BSA) as the host protein and were characterized by UV-visible spectroscopy, ESI-TOF mass spectrometry and molecular docking studies. The catalytic activities of the BSA-ML in the selective oxidation of various prochiral sulfides in aqueous media, using H₂O₂ as oxidant, have been evaluated. During the optimization process, pH and the concentrations of catalyst and oxidant were found to have a remarkable influence on both yield and enantioselectivity. In certain cases, BSA-ML gave satisfactory results in the oxidation of organic sulfides to sulfoxides (up to 100% conversion, 100% chemoselectivity, 96% ee and 500 h⁻¹ turnover frequency).

Artificial metalloenzymes have been prepared by non-covalent insertion of transition metal Schiff-base complexes into bovine serum albumin as the host protein and were characterized by UV-visible spectroscopy, ESI-TOF mass spectrometry and molecular docking studies.

Highly efficient aqueous phase reduction of nitroarenes catalyzed by phosphine-decorated polymer immobilized ionic liquid stabilized PdNPs

Phosphino-decorated polymer immobilised ionic liquid-stabilised PdNPs are highly efficient catalysts for the aqueous phase hydrogenation and transfer hydrogenation of aromatic nitro compounds in batch and continuous flow.

Two New Sandwich-Type Polyoxomolybdates Functionalized with Diphosphonates: Efficient and Selective Oxidation of Sulfides to Sulfones

Two sandwich-type polyoxomolybdates Na₈[MO₂{Mo₂O₅(O₃PCH₃C(O)PO₃)}₂] (M = Ni²⁺ (1); Co²⁺ (2)) were synthesized by one-pot reaction of Na₂HPMo₁₂O₄₀·14H₂O, 1-hydroxy ethidene diphosphonic acid (HEDP=HOC(CH₃)(PO₃H₂)₂), and (1) NiCl₂/CoCl₂ (2). Compounds 1 and 2 were characterized by single crystal X-ray analysis, X-ray powder diffraction (XRPD), IR spectroscopy, ³¹P NMR spectra, UV-vis spectroscopy, and thermogravimetric analyses (TGA). Structural analysis reveals that 1 and 2 exhibit similar centrosymmetric structure, which consists of one transition metal (TM) ion sandwiched by two same subunits {Mo₂O₅(O₃PCH₃C(O)PO₃)}. The clusters 1 and 2 show efficient catalytic activities for oxidation of thioanisole. Moreover, they are catalytically selective for oxidizing thioanisole. Both resuable polyoxomolybdates 1 and 2 catalysts show good thermo- and hydrolytic stability. It is noted that compound 1 shows outstanding catalytic activity for oxidation of various sulfides to corresponding sulfones with 93–100% selectivity at 97–100% conversion in one hour under mild conditions, which is potentially valuable to the removal of organic sulfides.

Mechanism of extractive/oxidative desulfurization using the ionic liquid inimidazole acetate: a computational study

The dual role of the ionic liquid 1-butyl-3-methyl-imidazolium trifluoroacetic acid ([C₄mim]TFA) as an extractant for thiophene (TH) and a catalyst for the oxidation of TH was explored at the molecular level by performing density functional theory (DFT) calculations. The calculated interaction energies demonstrated why [C₄mim]TFA is a better extractant for thiophene sulfone (THO₂) than for TH. Two pathways were proposed for the oxidation of TH to THO₂ with [C₄mim]TFA acting as a catalyst. In the dominant pathway, a peracid is formed which then oxidizes TH to the sulfoxide and sulfones. The presence of [C₄mim]TFA was found to greatly reduce the barrier to the oxidative desulfurization (ODS) of TH using H₂O₂ as an oxidant. Graphical Abstract Possible reaction mechanisms of TH with the aid of [C4mim]TFAᅟ.

Heteropolytungstostannate as a homo- and heterogeneous catalyst for Knoevenagel condensations, selective oxidation of sulfides and oxidative amination of aldehydes

Heteropolytungstostannate of [P₂W₁₈O₆₈(HOSn^IVOH)₃]¹²⁻ was grafted on amine levels coated magnetic nanoparticles and used as catalysis in the selective oxidation of sulfides and oxidative amination of aldehydes in an aqueous medium.