Design and synthesis of a novel chiral triptycene-based imine ligand for enantioselective epoxide ring-opening reactions

Abstract

A novel chiral triptycene-based imine ligand has been designed, synthesized and then characterized using various spectroscopic techniques, including FT-IR, ¹H NMR, ¹³C NMR, and HRMS. It was first coordinated with cobalt to form a cobalt(II) complex, followed by combination with various axial ligands, such as acetate, tosylate, triflate, α,α,α-trifluoro-p-toluate and chloride, to generate the corresponding cobalt(III) complexes. These complexes were further analysed using EDS to confirm the coordination with cobalt. All the triptycene-based cobalt complexes demonstrated high catalytic efficiency towards the ring-opening reaction of epoxides with aniline derivatives, yielding β-amino alcohols in very high yields (up to >99%) with appreciable enantiomeric ratios (up to 81 : 19).