Enabling the synthesis of perfluoroalkyl bicyclobutanes via 1,3 γ-silyl elimination.

Two new bicyclobutanes were prepared from cyclobutyl systems by a novel, solvolytic, carbocation-based methodology. An electron-withdrawing perfluoroalkyl group at the incipient cationic center enhances neighboring-group participation of the γ-silyl group, inducing facile, remarkably selective 1,3-elimination yielding only bicyclobutanes. The method unlocks potential access to a host of EWG-substituted strained rings and a potential new method for the synthesis of trifluoromethylcyclopropanes.