Synthesis of Seven‐Membered‐Ring Ketones by Arylative Ring Expansion of Alkyne‐Substituted Cyclobutanones

Ever-increasing circles: Seven-membered-ring ketones are constructed by a rhodium(I)-catalyzed arylative ring-expansion reaction of alkyne-substituted aryl cyclobutanones, in which two CC bond-forming and one CC bond-cleaving events occur consecutively (see scheme).