Metal-free reductive acyldifluoroalkylation of alkenes through cooperative NHC and organophotocatalysis

Abstract

Reductive alkene difunctionalization is a valuable strategy for complex molecule synthesis, but it typically requires a metal catalyst and stoichiometric amounts of a transition metal as the reducing agent. Herein, we introduce a reductive acyldifluoroalkylation method to synthesize β-difluoroalkyl ketones, which proceeds in a metal-free manner at room temperature. Meanwhile, this protocol overcomes the limitations in the synthesis of such compounds, which previously required heating or precious metal photocatalysts/oxidants. Besides, this reductive acyldifluoroalkylation reaction of alkenes, acyl fluorides and difluoroalkyl bromides, facilitated by cooperative NHC and organophotocatalysis, is also characterized by its mild conditions, broad substrate scope, and late-stage functionalization.