Novel [RhCl(CO)dppp}2]‐catalyzed intramolecular carbonylative [2+2+1] cycloadditions of bis(phenylsulfonylallene) derivatives under CO, leading to the facile formation of bis(phenylsulfonyl)bicyclo[n.3.0] frameworks (n=4–6), have been developed. The terminal double bonds of both allenyl moieties served exclusively as the two π‐components. In particular, this newly developed method was shown to be
No templates needed: The title reaction makes it easy to construct the bicyclo[6.3.0]undecadienone framework in high yields (see scheme). A template effect is not required to achieve this ring‐closing reaction efficiently. The present method can be applied to the construction of bicyclo[5.3.0] and bicyclo[4.3.0] ring systems. Ts=p‐toluenesulfonyl.