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.