A third generation of radical fluorinating agents based on N-fluoro-N-arylsulfonamides.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30459353.
- Also identified by DOI 10.1038/s41467-018-07196-9 and PMC identifier 6244228.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Radical fluorination has been known for a long time, but synthetic applications were severely limited by the hazardous nature of the first generation of reagents such as F<sub>2</sub> and the strongly electrophilic nature of the second generation of reagents such as N-fluorobenzenesulfonimide (NFSI) and Selecfluor<sup>®</sup>. Here, we report the preparation, use and properties of N-fluoro-N-arylsulfonamides (NFASs), a class of fluorinating reagents suitable for radical fluorination under mild conditions. Their N-F bond dissociation energies (BDE) are 30-45 kJ mol<sup>-1</sup> lower than the N-F BDE of the reagents of the second generation. This favors clean radical fluorination processes over undesired side reactions. The utility of NFASs is demonstrated by a metal-free radical hydrofluorination of alkenes including an efficient remote C-H fluorination via a 1,5-hydrogen atom transfer. NFASs have the potential to become the reagents of choice in many radical fluorination processes.