Rhodium(I)-catalyzed intramolecular carbonylative [2+2+1] cycloadditions and cycloisomerizations of bis(sulfonylallene)s.

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.