JOURNAL OF ORGANIC CHEMISTRY vol. 81, no. 16, pp. 7072 - 7079
AMER CHEMICAL SOC
SCI; SCIE; SCOPUS
Photoredox catalysis has emerged as a valuable alternative to dark-state catalysis. For the full potential of photoredox catalysis to be utilized, it is imperative to make use of low-energy photons in photoinduced radical processes. We have demonstrated that the use of oxalate as a coreactant provides a useful principle for the photocatalytic production of trifluoromethyl radicals (center dot CF3) from CF3I upon green or red LED photoirradiation of narrow-bandgap photocatalysts. The photo catalytic cycle involves a radical anion of carbon dioxide (CO2 center dot-) as a reductant for CF3I, which is generated through photoinduced oxidative decarboxylation of oxalate. Electrochemical characterizations and steady-state and transient photophysical investigations were performed to reveal that there are two photoinduced electron-transfer pathways for oxalate-mediated center dot CF3 generation.