Cu(III) Trifluoromethyl Complexes with 1,3-Diketonate Ligands and Their Versatile Reactivity in C-H Trifluoromethylation

High-valent Cu(III) trifluoromethyl complexes with 1,3-diketonates as bidentate oxygen donor ligands LCuIII(CF3)2 were prepared for the first time and fully characterized, including X-ray crystallography. These complexes are soluble in most organic solvents and were found to be more reactive than known N-donor Cu(III) trifluoromethyl complexes. They exhibit a promising reactivity in radical and radical-polar crossover trifluoromethylation reactions. Direct C-H trifluoromethylation of electron-rich arenes and indoles using Cu(III) trifluoromethyl diketonates under blue light irradiation in mild conditions is described. Azolo- and oxy-trifluoromethylation of terminal alkynes using Cu(III) trifluoromethyl diketonate complex and S-trifluoromethylation of thiophenol were demonstrated as applications.