Synthesis of planar chiral [2.2]paracyclophane-based bisoxazoline ligands bearing no central chirality and application to Cu-catalyzed asymmetric O–H insertion reaction

Abstract

C ₂-symmetric planar chiral [2.2]paracyclophane-based bisoxazoline ligands, characterized by the inserted benzene spacer, which has a sterically demanding substituent, were synthesized and it was shown that up to 80% ee was obtained for the Cu-catalyzed O–H insertion reaction of α-diazo esters without the aid of the central chirality.