Cationic Rh(I) catalyst in fluorinated alcohol: mild intramolecular cycloaddition reactions of ester-tethered unsaturated compounds.

In fluorinated alcohols, the cationic Rh(I) species, which is derived from [Rh(COD)Cl]2 and AgSbF6, efficiently catalyzed intramolecular [4+2] cycloaddition reactions of ester-tethered 1,3-diene-8-yne derivatives. The catalytic system was also effective in intramolecular [5+2] cycloaddition reactions of ester-tethered omega-alkynyl vinylcyclopropane compounds.