Photocatalyst‐Free Trifluoromethylation of Indolizines Through an Electron Donor–Acceptor Complex

The indolizine scaffold has attracted considerable interest owing to its broad potential in medicinal chemistry. We describe a photochemical trifluoromethylation that enables direct C‐3 functionalization of indolizines and imidazo[1,2‐ a ]pyridines without the use of a photocatalyst, allowing the reaction to proceed under milder and more environmentally friendly conditions. Mechanistic investigations support the in situ formation of an electron donor–acceptor (EDA) complex. The protocol exhibits broad functional group tolerance, delivering 27 C‐3 trifluoromethylated indolizine and imidazo[1,2‐ a ]pyridine derivatives with yields up to 82%, underscoring its synthetic robustness and versatility. Overall, this methodology simplifies the access to C‐3 functionalized indolizines and facilitates the exploration of new structures with potential biological relevance.