Visible-Light Photoredox-Catalyzed Decarboxylative Double Difluoromethylation of β,γ-Unsaturated Carboxylic Acids for the Synthesis of Difluoromethylated Allylic Compounds

The regioselective synthesis of double difluoromethylated allylic products from easily accessible beta,gamma-unsaturated carboxylic acids and difluoromethylation reagents under visible-light photocatalysis is reported. This transformation tolerates various bromodifluoroacetates and fluorinated phosphonates, providing access to various difluoromethylated allylic products in 54-93% yield with 80:20 to 99:1 Z/E, which can not be readily synthesized using the currently known methods. Choosing fac-[Ir(ppy)(3)] as the photocatalyst and 1,4-diazabicyclo[2.2.2]octane (DABCO) as the additive is crucial for the success of this transformation.

Automated summary

The regioselective synthesis of double difluoromethylated allylic products from easily accessible beta,gamma-unsaturated carboxylic acids and difluoromethylation reagents under visible-light photocatalysis is reported. This transformation tolerates various bromodifluoroacetates and fluorinated phosphonates, providing access to various difluoromethylated allylic products in 54-93% yield with 80:20 to 99:1 Z/E, which can not be readily synthesized using the currently known methods. Choosing fac-[Ir(ppy)(3)] as the photocatalyst and 1,4-diazabicyclo[2.2.2]octane (DABCO) as the additive is crucial for the success of this transformation.