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).
Galan
Brandon R
BR
Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA.
Rovis
Tomislav
T