Beyond Reppe: Building Substituted Arenes by [2+2+2] Cycloadditions of Alkynes

Synthetic sequel : The transition‐metal‐catalyzed 2+2+2] cycloaddition is an established method for the construction of carbocyclic frameworks but is often plagued by poor selectivity. Recent literature paints a promising picture—a more general metal‐catalyzed 2+2+2] cycloaddition can be accomplished intermolecularly using three separate alkynes to furnish highly substituted arenas (see scheme).