Pd(II)-Catalyzed Enantioselective Intramolecular Arylation of Unbiased C(sp)-H Bonds to Construct Chiral Benzo-ring Compounds.

The asymmetric synthesis of chiral benzo-ring containing compounds through enantioselective intramolecular arylation of unbiased methylene C(sp)-H bonds was reported. Judicious choice of non-C-symmetric chiral phosphoric acid (CPA) ligand is crucial for the high reactivity and enantioselectivity. The slight decrease in enantioselectivity at the late stage of the reaction was attributed to the hydrolysis of CPA ligands to the corresponding BINOL.