Electron Donor‐Acceptor Complex Driven Photocatalyst‐Free Trifluoromethylation of Heterocycles

Heterocyclic trifluoromethylation is efficiently initiated through a photochemical reaction utilizing an electron donor–acceptor (EDA) complex, proceeding smoothly without the use of photocatalysts, transition‐metal catalysts, or additional oxidants. This method has been optimized through extensive experimentation, demonstrating its versatility and efficacy across various substrates, including quinoxalinones, coumarins, and indolones. Notably, this approach enables the practical synthesis of trifluoromethylated quinoxalinones on a gram scale. Mechanistic investigations that incorporate radical trapping and ultraviolet/visible spectroscopy, confirmed the formation of the an EDA complex and elucidated the reaction pathways. This study highlights the crucial role of EDA photoactivation in trifluoromethylation, significantly expanding the application scope of EDA complexes in chemical synthesis. This study presents a novel Electron Donor‐Acceptor Complex (EDA) complex‐based method for trifluoromethylating heterocycles, bypassing traditional photocatalysts and oxidants. Utilizing 395 nm light, it efficiently produces trifluoromethylated quinoxalinones, coumarins, and indolones. The research emphasizes EDA photoactivation‘s crucial role, thoroughly documented through experimental, mechanistic, and spectroscopic analyses, thereby expanding EDA complexes′ utility in chemical synthesis.