Unstrained C–C bond activation and directed fluorination through photocatalytically-generated radical cations† †Electronic supplementary information (ESI) available: NMR spectra and computational data. See DOI: 10.1039/c5sc01973g Click here for additional data file

Unstrained C–C activation via putative radical cation formation promotes a directed radical fluorination event using Selectfluor, catalytic 9-fluorenone, and light. Expanding the repertoire of controlled radical fluorination techniques, we present a photosensitized unstrained C–C bond activation/directed monofluorination method using Selectfluor and 9-fluorenone. The reaction is amenable to the opening of multiple 1-acetal-2-aryl substituted rings to yield ω-fluoro carboxylic acids, esters, alcohols, and ketones with relative ease. Initial mechanistic insight suggests radical ion intermediates.