Making Full Use of the Oxidizing Equivalents in Bromate in the Selective Oxidation of Thiols, Sulfides, and Benzylic/Secondary Alcohols into Disulfides, Sulfoxides, and Aldehydes/Ketones

• DOI: 10.1021/ie901426t
• Publication Date: 2009-12-12T14:18:01Z
• Authors: Girdhar Joshi; Sukalyan Bhadra; Sudip Ghosh; Manoj K. Agrawal; Bishwajit Ganguly; Subbarayappa Adim...; Pushpito K. Ghosh; Brindaban C. Ranu
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

The oxidation of thiols to disulfides was achieved in high yields with 6:1 mol ratio of thiol to NaBrO3, while the oxidation of sulfides and benzylic/secondary alcohols to the corresponding sulfoxides and aldehydes/ketones was successfully undertaken with 3:1 mol ratio of substrate to NaBrO3. These ratios correspond to the minimum theoretical requirement of NaBrO3. The reactions were conducted at 0−30 °C, depending upon substrate, and were initiated with catalytic amounts of H+ and Br− (initial Br−/BrO3− = 1:3.5 for thiol oxidation and 1:8 for sulfide and alcohol oxidation). Further, regeneration and reuse of the spent reagent in the aqueous effluent was demonstrated.