Photo-cross-coupling reaction of electron-rich aryl chlorides and aryl esters with alkynes: a metal-free alkynylation

Photoheterolysis of aryl halides substituted with electron-donating groups (EDGs) or aryl esters in 2,2,2-trifluoroethanol (TFE) leads to phenyl cations, which can add to alkynes. This reaction is an appealing metal-free alternative to the (sila)-Sonogashira reaction.