Sonogashira-type cross-coupling reactions catalyzed by copper complexes of pincer N-heterocyclic carbenes

A new protocol for efficient cross-coupling of aryl- and heterocyclic iodides and aryl alkynes is developed in air using Cu-pincer bis(NHC) complexes with alkyl wingtips. The reaction involves oxidation of initial Cu(I)-NHC complexes, leading to a more active catalyst through generation of a high-valent Cu-oxygen intermediate.144