Visible Light‐Promoted Catalyst‐Free Difluoroalkylacylation of Alkenes Toward RCF2‐Functionalized Chroman‐4‐ones

Abstract We report a practical photochemical approach for alkene difluoroalkylacylation using easily available 2‐(allyloxy)arylaldehydes and bromodifluoroacetates (or bromodifluoroacetamides). This method features broad substrate scope and enables the efficient synthesis of various valuable RCF 2 ‐functionalized chroman‐4‐ones at room temperature. Key mechanistic insights show that the bifunctional bromodifluoroacetates (or bromodifluoroacetamides) act as both difluoroalkyl source and hydrogen atom acceptor. Consequently, the visible light‐driven difunctionalization of alkenes successfully proceeds without the need for external photocatalysts.