Visible-light induced transition-metal and photosensitizer-free conversion of aldehydes to acyl fluorides under mild conditions

Acyl fluorides are powerful synthons for acylation with wide application in the synthesis of valued compounds, especially peptides. Herein, a practical and catalyst-free method for the synthesis of acyl fluorides from aldehydes via C(sp2)–H fluorination is reported. This method enables the conversion of both aliphatic and aromatic aldehydes into acyl fluorides in good to excellent yields by visible-light under mild conditions in the absence of transition-metal and external photosensitizer. A variety of functional groups were well tolerated for this transformation. This green method provides a practical pathway to synthesize acyl fluorides under mild conditions.