A New Reagent for the Conversion of Thiols to Disulfides

Urea- Hydrogen Peroxide (UHP) Oxidation of Thiols to the Corresponding Disulfides Promoted by Maleic Anhydride as Mediator

“…Oxidative S-S coupling of thiols can be done under biological conditions in the presence of oxidants such as flavins and cytochromes [ 5 ]. In the laboratory thiols can be oxidized to corresponding disulfides by several oxidants such as: redox dyes [ 5 ], nitro compounds [ 6 ], diazocompounds [ 7 ], sulfoxides [ 8 ], halogens [ 9 ], 2-polyvinyl-pyridine/bromine complex [ 10 ], H 2 O 2 [ 11 ], KMnO 4 /CuSO 4 [ 12 ], DMSO/I 2 [ 1 a, 13 ], sodium perborate [ 14 ] and by electrochemical methods [ 15 ]. Due to the synthetic importance of disulfides, there has been an ongoing interest in new chemical and biotic methods [ 16 , 17 , 18 ].…”

Solvent free Oxidation of Thiols by (NH4)2Cr2O7 in the Presence of Mg(HSO4)2 and wet SiO2

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Oxidation of thiols to disulfides is well documented and wide range of reagents have been used for this conversion. [1][2][3][4][5][6][7][8][9] As is usually the case for every reagents used to date, some of the reported reagents suffer from disadvantages such as: long reaction time, availability, difficult work-up, preparation and instability. Conseqently, there is a need for protocols using readily available, safe and cheap reagents, leading to general and selective oxidation of thiols in good yields.We have already described the use of ammonium dichromate 10 (ADC) in the presence of Mg(HSO 4 ) 2 and wet SiO 2 11

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Oxidation in Fluoro Alcohols: Mild and Efficient Preparation of Disulfides from Thiols

“…Under the same conditions, 2-aminobenzenethiol (1e) afforded the corresponding disulfide 2e 15 in 96% yield, whereas its oxidation with polyvinylpyridine/bromine complex did not lead to the formation of the corresponding disulfide. 16…”