Rhodium-catalyzed selective [2 + 2 + 2] cyclizations of 1,6-diynes with monoynes leading to isoindolines and isobenzofurans

A highly efficient and selective [2 + 2 + 2] cyclization of diynes and monoalkynes was catalyzed by rhodium under room temperature in water/THF mixed solvent, affording isoindolines and isobenzofurans in good to excellent yields. The center atoms (N, O) in the diynes showed a significant effect for the cyclization.