Combined Rhodium‐Catalyzed Carbon–Hydrogen Activation and β‐Carbon Elimination to access Eight‐Membered Rings

Enlarge! CH bond activation and β-carbon elimination are combined in a net intramolecular hydroacylation of alkylidenecyclobutanes and alkylideneazetidines in the presence of rhodium catalysts, affording eight-membered-ring compounds in high yield (see scheme). This study demonstrates the possibility of exploiting the strain energy of azetidines through β-carbon elimination in new transition-metal-catalyzed reactions.