Synthesis of novel chiral heterogeneous bisoxazoline-based catalyst and itsapplication in the synthesis of chiral allylic esters by synchronousdehydrogenation and allylic oxidation of alkanes

Over the past couple of decades, chiral bisoxazoline (BOX) ligands, mainly prepared from the reaction of variousdicarboxylic acids and a range of chiral β-amino alcohols, have gathered increasing attention as promising ligands innumerous catalytic asymmetric transformations [۱, ۲]. Besides, according to the importance of recyclability of theseligands due to their high value, an excellent selection of a good substrate for immobilization of them could be a suitableidea. Herein, the new chiral amino bisoxazoline ligand was synthesized from the starting material ۵-nitro-isophthalicacid in several steps and then immobilized on the functionalized UiO-۶۶-NH۲ metal organic framework [۳]. Thestructure of synthesized chiral heterogeneous ligand was characterized by XRD, FE-SEM, BET, FT-IR and TGAtechniques. Finally, in order to investigate the catalytic activity of the prepared heterogeneous chiral ligand, it wasused in concurrent dehydrogenation of alkanes and allylic oxidation of alkenes as a rare synchronous reaction for thesynthesis of chiral allylic esters with various benzoic acid derivatives and oxidants under different conditions (Scheme۱) [۴, ۵]. The resulting chiral products were obtained in high yields and enantioselectivities

کلیدواژه ها:

Chiral bisoxazoline ligands ، Dehydrogenation ، Allylic oxidation ، Chiral allylic esters ، Functionalized UiO-۶۶-NH۲