Deracemization Enabled by Visible-Light Photocatalysis.

Deracemization is an ideal but challenging strategy for the conversion of a racemic mixture into a single enantiomer. Recent studies have demonstrated that visible-light photocatalysis could be utilized to promote selective deracemization of axially chiral allenes as well as cyclopropylquinolones and cyclic ureas with central chirality either through energy transfer or through a sequence of electron, proton, and hydrogen-atom transfer.