Copper-Catalyzed <i>trans</i>-Carbohalogenation of Terminal Alkynes with Functionalized Tertiary Alkyl Halides

A highly <i>trans</i>-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 <i>trans</i>-carboalkynylation process has been achieved via the tandem <i>trans</i>-carbohalogenation/Sonogashira coupling reaction, which furnishes highly functionalized 1,3-enynes in a single chemical transformation