ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
1/1
0/0

Intermediacy of Copper(I) under Oxidative Conditions in the Aerobic Copper-Catalyzed Decarboxylative Thiolation of Benzoic Acids

preprint
submitted on 25.09.2019 and posted on 27.09.2019 by Kerry-Ann Green, Jessica Hoover
Despite the growing importance of oxidative decarboxylative coupling (ODC) reactions, they often require silver salts to serve as both oxidant and decarboxylation mediator. The use of O2 in place of silver would be ideal, yet there are few examples of aerobic variants and they are not well understood mechanistically. Here, we disclose a mechanistic study of the Cu-catalyzed aerobic decarboxylative thiolation reaction, and propose a pathway that involves the intermediacy of Cu(I) species, even under these oxidizing conditions. Decarboxylation from a Cu(I) carboxylate appears to be turn-over-limiting. Cu(II) carboxylates are not competent intermediates, indicating an alternative role for O2. We propose that O2 is responsible for oxidizing a Cu(I) thiolate intermediate to release tightly bound thiolate ligands. To the best of our knowledge, this is the first example of a kinetic study of an ODC reaction and may have implications for the development of related Cu-catalyzed decarboxylation reactions.

Funding

CHE-1454879

CHE-1228336

History

Email Address of Submitting Author

jmhoover@mail.wvu.edu

Institution

West Virginia University

Country

United States

ORCID For Submitting Author

0000-0003-0254-5090

Declaration of Conflict of Interest

The authors declare no conflict of interest.

Exports