Fe₃O₄/PEG-SO₃H as a heterogeneous and magnetically-recyclable nanocatalyst for the oxidation of sulfides to sulfones or sulfoxides

Abstract

We present below a sulfonated-polyethylene glycol-coated Fe3O4 nanocomposite (Fe3O4/PEG-SO3H) as a greatly effective and ecological nanocatalyst for the selective oxidation of sulfides to sulfoxides or sulfones with brilliant yields under solvent-free conditions by employing 30% hydrogen peroxide as the oxidant.

Reusable BNPs‐SiO2@(CH2)3NHSO3H‐catalysed selective oxidation of sulfides to sulfones

“…[29] 30 min 85 SCHEME 3 Proposed mechanism of oxidation of sulfides to sulfones FIGURE 7 FT-IR spectra of the catalyst after one run and after five runs The mixture stirred for 0.5 h during which the pH of the solution decreased to 2.00, indicating an ion exchange between sulfonic acid protons and sodium ions, this being equal to a loading of 1 mmol g −1 of sulfonic acid groups.…”

“…The mixture stirred for 0.5 h during which the pH of the solution decreased to 2.00, indicating an ion exchange between sulfonic acid protons and sodium ions, this being equal to a loading of 1 mmol g −1 of sulfonic acid groups. [29] 30 min 85 SCHEME 3 Proposed mechanism of oxidation of sulfides to sulfones FIGURE 7 FT-IR spectra of the catalyst after one run and after five runs…”

“…[14] Boehmite nanoparticles (BNPs) have several advantages, such as non-toxicity, ready availability, high dispersion of active phases, thermal and mechanical stability and high surface area, resulting in high catalyst loading capacity. [19][20][21][22][23][24][25][26][27][28][29][30][31] It should be noted that these procedures have some disadvantages, such as the inability for selective oxidation of sulfides, reactivity towards other functional groups, use of excess amount of oxidant with respect to substrates, lack of reusability of catalyst, use of organic solvents, low yields, expensive oxidants and harsh reaction conditions. [16,17] The derivatives of heteroaryl sulfones constitute core units of many important molecules which are used as drugs and potential precursors [18] (Figure 1).…”

“…Several homogeneous and heterogeneous oxidant-based catalytic systems have been reported for the oxidation of sulfides. [19][20][21][22][23][24][25][26][27][28][29][30][31] It should be noted that these procedures have some disadvantages, such as the inability for selective oxidation of sulfides, reactivity towards other functional groups, use of excess amount of oxidant with respect to substrates, lack of reusability of catalyst, use of organic solvents, low yields, expensive oxidants and harsh reaction conditions. [32][33][34][35] Hydrogen peroxide is an attractive and environmentally benign oxidant for the oxidation of sulfides, because it is inexpensive, easy to handle, safely stored, soluble in water and many organic solvents and produces only water as a side product.…”

Butane‐1‐sulfonic acid immobilized on magnetic Fe3O4@SiO2 nanoparticles: A novel and heterogeneous catalyst for the one‐pot synthesis of barbituric acid and pyrano[2,3‐d] pyrimidine derivatives in aqueous media

“…In recent years the use of magnetic nanoparticles (MNPs) for the preparation of supported heterogeneous catalysts has attracted significant attention. [1][2][3][4][5][6][7][8][9][10][11][12] This attention can be attributed to the unique properties of these types of compounds including high thermal and mechanical stability, large surface area to volume ratio, low toxicity, ease of recovery by use of an external magnetic field and well-defined pore size distribution. [13] In this regard magnetic metal oxide nanoparticles and especially Fe 3 O 4 nanoparticles have been the focus of much research recently.…”