Scientists of the Zelinsky Institute have developed a photocatalytic method for the thiolation of carboxylic acids

Currently, photoredox-catalyzed processes are being actively studied all over the world. Their main advantages are mild conditions, environmental friendliness, and compatibility with most functional groups. Scientists of the Laboratory of Functional Organic Compounds have developed a photoredox thiolation of carboxylic acids using disulfides with a tetrafluoropyridine fragment. The classical interaction of disulfides and carboxylic acids is often difficult. This is due to the formation of thiols during the reaction, which promote the undesirable process of a hydrogen atom transfer to the alkyl radical generated from the acid. As a result, the main product of the reaction will be an alkane, and not the target sulfide. Due to the use of a disulfide with a tetrafluoropyridine fragment by the researchers of the ZIOC it was possible to carry out a selective process for the formation of a carbon–sulfur bond. It is obvious that the reaction is possible due to the influence of fluorine atoms, which provide a favorable balance between the stages of the competitive transfer of a hydrogen atom and the transfer of a sulfide group. The developed approach makes it possible to successfully introduce into the reaction primary, secondary, tertiary, and heteroatom-substituted carboxylic acids, including natural polyfunctional compounds.

Source:

Mikhail O. Zubkov, Mikhail D. Kosobokov, Vitalij V. Levin, Alexander D. Dilman Photocatalyzed Decarboxylative Thiolation of Carboxylic Acids Enabled by Fluorinated Disulfide Org. Lett., 2022, 24, 2354–2358. DOI: 10.1021/acs.orglett.2c00549.