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

C2-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.