Copper-catalyzed regio- and stereoselective fluorocarboalkynylation of alkynes

It is attractive to establish an efficient and practical platform affording functional compounds using readily available feedstocks as starting materials under mild conditions. We describe a direct copper-catalyzed fluorocarboalkynylation of the readily available alkynes with excellent regio- and stereoselectivity. A wide range of conjugated trifluoromethyl 1,3-enynes were obtained in good yields by this operationally simple strategy. The mechanistic experiments and DFT calculation revealed that a radical-mediated process was involved in the catalytic cycle.