Synthesis of Unsymmetrical Disulfides

  • Author: Chemistry – An Asian Journal
  • Published Date: 27 June 2019
  • Source / Publisher: Chemistry – An Asian Journal/Wiley-VCH
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA
thumbnail image: Synthesis of Unsymmetrical Disulfides

Disulfide syntheses can be difficult because mixtures of thiols generally produce all possible symmetrical and unsymmetrical disulfides during coupling reactions. Prasenjit Mal, National Institute of Science Education and Research (NISER), Bhubaneswar, India, and colleagues have developed an umpolung (reversal of polarity) approach for the synthesis of unsymmetrical disulfides. In their approach, the usually nucleophilic sulfur is converted to an electrophilic sulfenium ion.

The electrophilic sulfenium ions were generated in situ from electron-rich thiols. These sulfenium ions are more stable than those generated from electron-deficient thiols, which makes the reaction selective. The reaction was performed using iodine as a catalyst, a 4-dimethylaminopyridine (DMAP)/water mixture as a promoter, and ethanol as the solvent. Electron-deficient thiols then react with the sulfenium ions.

A subsequent oxidation in air leads to the selective formation of the desired unsymmetrical disulfides (pictured). The reaction has a broad substrate scope and is performed in a single step under metal-free and mild conditions.


Article Views: 2084

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

If you would like to reuse any content, in print or online, from, please contact us first for permission and consult our permisson guidance prior to making your request

Follow on Facebook Follow on Twitter Follow on YouTube Follow on LinkedIn Follow on Instagram RSS Sign up for newsletters

Magazine of Chemistry Europe (16 European Chemical Societies) published by Wiley-VCH