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 pi-components. In particular, this newly developed method was shown to be a powerful tool for the construction of bicyclo[6.3.0]undecadienones, which have hardly been prepared by the known Pauson-Khand (-type) reactions. The bicyclo[7.3.0]dodecadienone homologue (one extra carbon) could be formed in rather low yields. Alternatively, novel cycloisomerizations of bis(phenylsulfonylallene) derivatives with catalysis by the same Rh(I) complex under N(2) readily produced the 3,4-dimethylene-2,5-bis(phenylsulfonyl)cyclononene and the corresponding cyclooctene and cycloheptene frameworks.

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.

The thermal reaction of 1,4-bisallenes with the aid of Cu salt/amine significantly suppressed the formal [3,3] sigmatropic rearrangement resulting in the highly selective formation of the bicyclo[4.2.0]octadiene framework. This reaction could be applied to the one-pot synthesis of bicyclo[4.2.0]octadienes from 1,5-hexadiynes via the Crabbé homologation.

Ohne Templat: Die Titelreaktion führt leicht und in hohen Ausbeuten zu Bicyclo[6.3.0]undecadienonen (siehe Schema), wobei der Ringschluss auch ohne Templateffekt effizient abläuft. Die vorgestellte Methode kann zum Aufbau von Bicyclo[5.3.0]‐ und Bicyclo[4.3.0]‐Ringsystemen verwendet werden. Ts=p‐Toluolsulfonyl.

Rhodium(I)-Catalyzed Intramolecular Carbonylative [2 + 2 + 1] Cycloadditions and Cycloisomerizations of Bis(sulfonylallene)s. -Carbonylative intramolecular cycloadditions of bis(sulfonylallenes), e.g. (I), (XIII) result in formation of bicyclo[n.3.0]alkadienones. Cycloisomerizations proceed under similar conditions, but in the absence of carbon monoxide monocyclic compounds are formed. -(KAWAMURA, T.; INAGAKI, F.; NARITA, S.; TAKAHASHI, Y.; HIRATA, S.; KITAGAKI, S.; MUKAI*, C.; Chem. Eur.