Aerobic Oxidation of Thiols to Disulfides Catalyzed by Trichlorooxyvanadium

Abstract

Oxidative coupling of thiols to disulfides is of interest from both a synthetic and a biological point of view, because disulfides are useful reagent in organic synthesis [1][2][3] and essential moieties of biologically active compounds for peptide and protein stabilization.4) Thiols can be easily over-oxidized, and therefore, several selective methods of converting thiols into disulfides have been developed. For example, iodine/ hydrogen iodide, 5) bromine, 6,7) potassium permanganate/copper(II) sulfate, 8) hydrogen peroxide in trifluoroethanol, 9) and dimethyl sulfoxide [10][11][12] are used for this purpose. Most of the existing methods suffer from drawbacks such as the use of stoichiometric amounts of reagents that generate undesirable waste materials. To overcome these drawbacks, catalytic oxidation using oxygen as a co-oxidant has been developed by several groups. [13][14][15][16][17][18]

Aerobic Oxidation of Thiols to Disulfides by Silver‐Based Magnetic Catalyst

“…Whereas, the necessity of oxidant for the formation of disulfide was ruled out when 100% yield of product was obtained in the absence of oxidant (Table , entry 3). Literature precedents also suggest that aerial oxygen can acts as oxidant for the synthesis of disulfide ,. Hence, the presence of catalyst is not only the limiting factor, but the presence of air is also absolutely necessary.…”

7.28 Oxidation of Sulfur, Selenium, and Tellurium

“…Moreover, in view of the environmental concerns, dioxygen is a highly appealing oxidant that is regarded as a green and sustainable reagent. Mo(VI), 5 V(V), 6 Mn(III)-Schiff base, 7 and Fe(III)-metal organic frameworks (MOF) 8 complexes recently proved to be useful catalysts in this process. Substrates less prone to be oxidized are tertiary alkyl thiols, which are generally isolated in moderate yield after prolonged reaction time.…”

“…Photooxidation of diaryl selenoxides with a stoichiometric amount of dimethyl sulfide in CH 2 Cl 2 with methylene blue at 0 1C using a 300 W Xenon lamp affords the selenones in high yield. 368 An alternative reagent for the oxidation of diaryltellurols is aqueous potassium ferricyanide (K 3 Fe(CN) 6 ), which enables the isolation of the corresponding ditellurides in good-to-high yield (Scheme 53). 373 A specific example of the oxidative approach to ditellurides is illustrated in the oxidation of 1-unsubstituted or 1-phenyl-1H-isotellurochromenes with MCPBA, which resulted in a ring-opening reaction to afford the corresponding o-formyl or benzoyl distyryl ditellurides (Scheme 54).…”

Synthesis of Heterocyclic Compounds through Palladium-Catalyzed C–H Cyclization Processes

“…The palladium catalyst may also be involved in this oxidation step, because the heating of 17a in DMSO at 120°C in the absence of palladium resulted in the formation of disulfide 19a in only 11% yield. 62,63,[65][66][67] Disulfide 19 formed from the corresponding ethenethiol 17 may undergo oxidative addition to palladium, leading to complex 20. 68,69) Subsequent C-H cyclization can give rise to the desired benzo[b] thiophene 18.…”