Iron(II) triflate as a photocatalyst for trifluoromethylation of functionalized arenes under blue LED light: Access to bioactive compounds

The trifluoromethyl group (-CF3) containing motifs are valuable leads for the small molecule drug discovery process and have multiple applications in medicine, agriculture, and material science. Not many CF3-containing motifs are commercially accessible; therefore, it is critical to design more advanced building blocks. In this work, we demonstrate an oxidant-free, scalable, and user-friendly protocol for the direct C(sp2)-H trifluoromethylation of functionalized arenes using Iron(II) triflate as a robust photocatalyst and bench-stable CF3SO2Na (1.5 equiv.) as a CF3 source under blue light irradiation. This method was extrapolated to >30 examples and compatible with potential functional groups (-NO2, -NH2, OH, -CHO, -CO2H, halogens, etc.). Notably, the utility of this approach is showcased for the synthesis of novel CF3-containing synthetic building blocks and a few bioactive compounds.