Access to Chiral Bisphenol Ligands (BPOL) through Desymmetrizing Asymmetric Ortho-Selective Halogenation

Privileged chiral catalyst scaffolds are highly useful in chemical synthesis such as drug preparation. Substituted phenol ligands are among the most frequently used scaffolds. However, the preparation of chiral phenol ligands commonly involves tedious synthetic procedures. Herein, we describe a facile strategy to prepare potent chiral bisphenols (BPOLs) through the desymmetrizing asymmetric ortho-halogenation. Both theoretical and experimental studies were conducted in order to shed light on the mechanistic picture. The halogen handles in the BPOL products are manipulated to yield unsymmetrical chiral BPOL ligands, which are potential privileged catalyst scaffolds and have been applied in other asymmetric catalytic reactions.