Chromium(III)-Catalyzed Desymmetrization of meso -Epoxides via Remote Stereocontrol: Synthesis of Chiral Fluorenes Bearing All-Carbon Quaternary Stereocenters.

An asymmetric desymmetrization of fluorene-derived meso -epoxides is disclosed for the construction of chiral fluorenes bearing an all-carbon quaternary stereocenter at C9. This desymmetrization is catalyzed by a chiral (salen)Cr III complex via remote stereocontrol, producing diverse chiral fluorenes with excellent yields and stereoselectivity. The practicality of this protocol was demonstrated through the transformation of the obtained products to some intriguing enantioenriched polymerizable monomers.