Fe3O4 as a magnetically reusable Fenton nanocatalyst for the oxidation of thiols to sulfonic acid and sulfides to sulfoxides and sulfones

Abstract

In this study, the oxidation of thiols to sulfonic acids and sulfides to sulfoxides and sulfones was carried out in the presence of Fe 3 O 4 /H 2 O 2 as an efficient heterogeneous Fenton system. The products were obtained in good to excellent yields and short reaction times. Further results showed that the heterogeneous catalyst could be recovered easily using an external magnetic field and reused several times without any loss of its catalytic activity.

Synthesis and conformational preferences of peptides and proteins with cysteine sulfonic acid

“…2d), 46 but this chemistry is potentially limiting in more complex peptides. Other recent methods for this transformation include the use of iron nanoparticles in refluxing MeCN or refluxing EtOH, 47 or oxone or KBrO 3 for extended reaction times (48–72 h). 48 All of these methods have substantial drawbacks, especially in the synthesis of larger peptides with a diverse array of functional groups.…”

“…46,102 (e) Conversion of Cys(SH) to Cys(SO 3 H) using Fe 3 O 4 magnetic nanoparticles (MNPs)/H 2 O 2 in CH 3 CN or EtOH. 47 (f ) Oxidation of Ac-Cys(SH)-OMe to Ac-Cys(SO 3 H)-OMe using oxone/NaHCO 3 or KBrO 3 . 48 (g) Conversion of thiols to sulfonic acids using H 2 O 2 and MeReO 3 (MTO).…”

“…(d) Conversion of cysteine thiol in a peptide to cysteine sulfonic acid, using H 2 O 2 and FeSO 4 46,102. (e) Conversion of Cys(SH) to Cys(SO 3 H) using Fe 3 O 4 magnetic nanoparticles (MNPs)/H 2 O 2 in CH 3 CN or EtOH 47. (f ) Oxidation of Ac-Cys(SH)-OMe to Ac-Cys(SO 3 H)-OMe using oxone/NaHCO 3 or KBrO 3 48.…”