Visible light-promoted metal-free C-H activation: Diarylketone-catalyzed selective benzylic mono- and difluorination

Ji Bao Xia, Chen Zhu, Chuo Chen

Research output: Contribution to journalArticle

275 Scopus citations


We report herein an operationally simple method for the direct conversion of benzylic C-H groups to C-F. We show that visible light can activate diarylketones to abstract a benzylic hydrogen atom selectively. Adding a fluorine radical donor yields the benzylic fluoride and regenerates the catalyst. The selective formation of mono- and difluorination products can be achieved by catalyst control. 9-Fluorenone catalyzes benzylic C-H monofluorination, while xanthone catalyzes benzylic C-H difluorination. The scope and efficiency of this new C-H fluorination method are significantly better than those of the existing methods. This is also the first report of selective C-H gem-difluorination.

Original languageEnglish (US)
Pages (from-to)17494-17500
Number of pages7
JournalJournal of the American Chemical Society
Issue number46
Publication statusPublished - Nov 20 2013


ASJC Scopus subject areas

  • Chemistry(all)
  • Catalysis
  • Biochemistry
  • Colloid and Surface Chemistry

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