A bioinspired route to indanes and cyclopentannulated hetarenes via (3+2)-cyclodimerization of donor-acceptor cyclopropanes.

A novel Lewis acid-catalyzed domino (3+2)-cyclodimerization of 2-arylcyclopropane-1,1-diesters and related stepwise cross-reaction of two different cyclopropanes were developed. These processes provide efficient and highly stereoselective access to polyoxygenated indanes and cyclopentannulated heteroarene derivatives, which display significant cytotoxicity against several lines of cancer cells (IC50 of 10(-6)-10(-5) M) while being non-toxic for normal cells.