Demethylenation of Cyclopropanes via Photoinduced Guest-to-Host Electron Transfer in an M6 L4 Cage.

Unusual demethylenation reactions of cyclopropanes under UV-light irradiation were found within a cavity of a photoactive coordination cage. The reaction proceeded via a guest-to-host electron transfer owing to the highly electron-deficient nature of the cage. The reactions were highly chemoselective and enabled late-stage derivatization of a steroid molecule, which led to a totally new un-natural steroid.