Photoredox/CopperCooperatively Catalyzed Arylalkynylationof [1.1.1]Propellane

We present a sp²–sp³/sp³–sp bond formation reaction through a three-component coupling strategy involving terminal alkynes, [1.1.1]­propellane, and aryl thianthrenium salts that are prepared from arenes. The reaction employs a dual photo/copper catalysis system and provides a streamlined approach for assembling 1-alkynyl-3-aryl bicyclo[1.1.1]­pentane derivatives with a broad spectrum of functional group compatibility. Mechanistic studies suggest that the generation of aryl radicals and copper alkynide intermediates was involved.