BrCF2CN for photocatalytic cyanodifluoromethylation

Abstract

Considering the unique electronic properties of the CF₂ and the CN groups, the CF₂CN group has significant potential in drug and agrochemical development, as well as material sciences. However, incorporating a CF₂CN group remains a considerable challenge. In this work, we disclose a use of bromodifluoroacetonitrile (BrCF₂CN), a cost-effective and readily available reagent, as a radical source for cyanodifluoromethylation of alkyl alkenes, aryl alkenes, alkynes, and (hetero)arenes under photocatalytic conditions. This protocol demonstrates an exceptionally broad substrate scope and remarkable tolerance to various functional groups. Notably, the cyanodifluoromethylation of alkynes predominantly provides sterically hindered alkenes, a thermodynamically unfavorable outcome, and (hetero)arene C-H bonds are directly amenable to cyanodifluoromethylation without pre-functionalization.