The Photoinduced Metal-Free Hydrotrifluoromethylation of Vinyl Phosphonates or Phosphine Oxides

We describe a simple and metal-free photochemical strategy for the direct hydrotrifluoromethylation of vinyl phosphonates or phosphine oxides by sodium triflinate under ultraviolet or visible light irradiation. Acetone and diacetyl were used as radical initiators to generate CF3 radicals that were efficiently added to vinyl phosphonates or phosphine oxide to yield beta-trifluoromethylated phosphorus compounds without the use of any catalyst. A broad scope of substrates scope is demonstrated in moderate to excellent yields. Mechanistic experiments were performed to study the source of hydrogen; the results indicate that H2O in the solvent or additive is the primary hydrogen source.