Photoinduced Asymmetric Formal Siloxycarbene Insertion into sp 3 C-H Bonds Enabled by Chiral Phosphoric Acid.

We disclosed herein an enantioselective formal siloxycarbene insertion reaction enabled by chiral phosphoric acid and blue LED irradiation. This is the first time the asymmetric siloxycarbene insertion into an sp 3 C-H bond under transition-metal free conditions has been realized. The reaction features good isolated yields (up to 92%), high enantioselectivity (up to 99:1 er ), mild reaction conditions, and good compatibility. Moreover, this method also provides a green and efficient method to construct a chiral quaternary carbon center.