Visible Light-Induced Borylation of C-O, C-N, and C-X Bonds

J Am Chem Soc. 2020 Jan 22;142(3):1603-1613. doi: 10.1021/jacs.9b12519. Epub 2020 Jan 10.


Boronic acids are centrally important functional motifs and synthetic precursors. Visible light-induced borylation may provide access to structurally diverse boronates, but a broadly efficient photocatalytic borylation method that can effect borylation of a wide range of substrates, including strong C-O bonds, remains elusive. Herein, we report a general, metal-free visible light-induced photocatalytic borylation platform that enables borylation of electron-rich derivatives of phenols and anilines, chloroarenes, as well as other haloarenes. The reaction exhibits excellent functional group tolerance, as demonstrated by the borylation of a range of structurally complex substrates. Remarkably, the reaction is catalyzed by phenothiazine, a simple organic photocatalyst with MW < 200 that mediates the previously unachievable visible light-induced single electron reduction of phenol derivatives with reduction potentials as negative as approximately - 3 V versus SCE by a proton-coupled electron transfer mechanism. Mechanistic studies point to the crucial role of the photocatalyst-base interaction.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Boronic Acids / chemistry*
  • Carbon / chemistry*
  • Catalysis
  • Light*
  • Nitrogen / chemistry*
  • Oxygen / chemistry*


  • Boronic Acids
  • Carbon
  • Nitrogen
  • Oxygen