Copper-catalyzed trans-carbohalogenation of terminal alkynes with functionalized tertiary alkyl halides.

A highly trans-selective Cu-catalyzed carbohalogenation including carbobromination, carboiodination, and carbochlorination of terminal alkynes with activated tertiary alkyl halides has been realized, providing quaternary-carbon-containing alkenyl halides in good yields with excellent regio- and stereoselectivity. Meanwhile, an unprecedented alkyne trans-carboalkynylation process has been achieved via the tandem trans-carbohalogenation/Sonogashira coupling reaction, which furnishes highly functionalized 1,3-enynes in a single chemical transformation.