Application of Chiral Biphenyl Bisoxazoline Ligands in the present of HZSM-5 as additive in Catalytic Asymmetric Allylic Oxidation of Cyclohexene

The copper-catalyzed allylic oxidation of olefins with peresters has been the subject of numerous synthetic investigations. This reaction provides access to chiral allylic alcohols that are the key intermediates in natural product synthesis [1]. The literature survey shows that the chiral C2-symmetric bisoxazolines (box‘s) are one of the most effective and popular classes of chiral ligands studied to copper-catalyzed allylic oxidations, and their application has made a major breakthrough with drastic improvement in enantioselectivity and yield [1, 2]. Herein, chiral biphenyl bisoxazoline ligands were synthesized from 2-amino benzoic acid and potential of these ligands for copper-catalyzed allylic oxidations of cyclohexenewas investigated in the Presence of HZSM-5 as additive [3]. In summary, HZSM-5 as additive was examined for oxidation ofcyclohexene, high catalytic activities, enantioselectivities up to 82% and 99% yield were obtained by using this combination of additives (Figure1).