Integrating Organic Lewis Acid and Redox Catalysis: The Phenalenyl Cation in Dual Role

J Am Chem Soc. 2018 Jul 5;140(26):8330-8339. doi: 10.1021/jacs.8b04786. Epub 2018 Jun 22.

Abstract

In recent years, merging different types of catalysis in a single pot has drawn considerable attention and these catalytic processes have mainly relied upon metals. However, development of a completely metal free approach integrating organic redox and organic Lewis acidic property into a single system has been missing in the current literature. This study establishes that a redox active phenalenyl cation can activate one of the substrates by single electron transfer process while the same can activate the other substrate by a donor-acceptor type interaction using its Lewis acidity. This approach has successfully achieved light and metal-free catalytic C-H functionalization of unactivated arenes at ambient temperature (39 entries, including core moiety of a top-selling molecule boscalid), an economically attractive alternative to the rare metal-based multicatalysts process. A tandem approach involving trapping of reaction intermediates, spectroscopy along with density functional theory calculations unravels the dual role of phenalenyl cation.

Publication types

  • Research Support, Non-U.S. Gov't