Copper-catalyzed radical trifluoromethylalkynylation of unactivated alkenes with terminal alkynes

A copper-catalyzed three-component radical trifluoromethylalkynylation of unactivated alkenes is realized from Togni-II reagent and readily available terminal alkynes under mild conditions to afford an array of beta-tri- fluoromethylated alkynes. The utilization of a multidentate N,N,N-ligand is crucial for the efficient radical generation and the C(sp3)-C(sp) bond formation. Facile transformations of the difunctionalization products highlight its potential utility in the synthesis of various trifluoromethyl-containing building blocks.