Less catalyst, lower temperature, and greater generality are the advantages of the new general protocol over those previously described for the palladium-catalyzed coupling of aryl chlorides and alkynes. Better results are obtained without a copper cocatalyst, which has been found to inhibit product formation in the coupling reaction of aryl chlorides with terminal alkynes.
“Efficient Palladium-Catalyzed Coupling of Aryl Chlorides and Tosylates with Terminal Alkynes: Use of a Copper Cocatalyst Inhibits the Reaction”, Angew. Chem. Int. Ed., 2003, 42(48), 5993-5996.