Synthesis of rigid chiral C3-symmetric triptycene-based ligands and their application in enantioselective Cu(I)-catalyzed aziridination of chalcones

Abstract

The design and synthesis of C3- symmetric or pseudo-C3-symmetric ligands present a particular challenge because the molecular frames available for fitting C3 symmetry are rare. Herein, we report on the synthesis and characterization of new C3-symmetric tripodal TripTOX ligands, based on the rigid triptycene backbone, and on their successful application in the asymmetric copper-catalyzed aziridination reaction. The ligand showed good to excellent performance in the copper-catalyzed asymmetric aziridination of chalcones. The catalyst derived from the new ligand appears to be the catalyst of choice when substrates have a coordinating nature.