Enantioselective Synthesis of β,γ‐Unsaturated α‐Fluoroesters Catalyzed by N‐Heterocyclic Carbenes

NHC meets F: NHC-bound enolates undergo a catalytic asymmetric fluorination reaction to β,γ-unsaturated α-fluoroesters, which are obtained with good efficiency and stereoselectivity (see scheme, NFSI=N-fluorobenzenesulfonimide). The strategy overcomes possible challenges, such as fluorination in the γ position and difluorination. Experimental evidence combined with DFT calculations provides insight into the reaction mechanism.