Sulfone Activation Triggered by Iodide Anion for Photoinduced Fluoroalkylations

Radical fluoroalkylation via electron donor-acceptor (EDA) complex photochemistry stands out as a particularly attractive approach, owing to its mild conditions and the absence of an external metal photocatalyst or organic dye. Fluoroalkyl sulfones, valued for their stability, accessibility, and structural tunability, have emerged as versatile precursors for radical fluoroalkylation. Herein, we present a photocatalyst-free and straightforward method for direct fluoroalkylation through an EDA complex, utilizing inexpensive iodide anion as an electron donor and fluoroalkyl sulfones as acceptors. Upon visible light irradiation, the EDA complex undergoes single-electron transfer (SET) to generate fluoroalkyl radicals, which subsequently react with a diverse array of silyl enol ethers with high efficiency. The method features mild reaction conditions, broad functional group compatibility, and an extensive substrate scope that encompasses bioactive molecules and sterically demanding architectures. Mechanistic investigations indicate the involvement of an iodide-mediated EDA complex and support the proposed radical-generation pathway. This work establishes a practical and sustainable platform for fluoroalkylation, underscoring the utility of iodide in EDA-based photochemistry and broadening the scope of radical synthetic methods.