Copper‐Catalyzed Trifluoromethylalkynylation via Radical‐Mediated Multicomponent Process

ABSTRACT Multicomponent reactions (MCRs) are powerful tools for the rapid construction of complex molecules, as they enable the assembly of diverse functional fragments into a single skeleton. Herein, we report an efficient and practical copper‐catalyzed multicomponent radical process that couples readily available Togni's reagent II, alkenes, and alkynes to afford β‐trifluoromethyl propynes with high regioselectivity. Under mild copper‐catalyzed conditions, this strategy enables chemoselective and regioselective radical trifluoromethylalkynylation of alkenes while suppressing undesired copper‐catalyzed or radical‐mediated side reactions. The method exhibits a broad substrate scope for both alkenes and alkynes, with excellent functional group compatibility.