Camphor Oxazoline Ligands Derived From The Synthesis And Characterization

As chemists continue to explore and study, the special functions of chiral compound have been gradually realized in medical treatment, chemical, biological and other related fields. Then, some efforts were made to the synthesis of chiral compounds. Chemists have paid much attention to the catalytic asymmetric synthesis, because it can efficiently produce a large number of new optically active substances with only catalytic amount of chiral compounds. It’s also one of the most convenient methods to prepare optically active compounds and has become the current international research focus.Chiral catalyst is the key to catalytic asymmetric synthesis. Chiral ligands as chiral inducing reagents can make an effective asymmetric induction and control the configuration of the reaction intermediates. Chiral ligand is a crucial factor affecting stereoselectivity. To design some chiral ligands with simple structures, high catalytic selectivity and facile synthesis is the eternal subject in asymmetric synthesis.In recent years, a large number of chiral ligands containing P, N, S, O and other coordination atoms have been developed. Oxazoline, a five-membered heterocyclic ring containing both N and O coordinated atoms, is an excellent class among nitrogen-containing chiral ligands. Since the1980s, the scientist have synthesized a number of chiral oxazoline ligands, and used them in a variety of asymmetric catalytic reactions, such as the asymmetric Henry reaction, cyclopropanation of olefins and imines, the Diels-Alder reaction, Friedel-Crafts reaction, nucleophilic addition to imines and aldehydes, and hydrosilylation.Natural chiral compounds have inherent chiral center, therefore the desired chiral ligands can be more convenient prepared from some natural chiral compounds. Due to its unique steric structure and electronic effect, camphor compounds have been widely applied to asymmetric synthesis reactions, showing excellent enantioselectivity. Based on the above reasons, we choose to synthese oxazolines with camphor skeleton from natural camphor.The thesis consists of three parts:The first chapter reviewed the research progress of oxazoline ligands classification, application and synthesis. The second chapter is the preparation and characterization of six aromatic nitriles by different approaches. In the third chapter,1-amino-2-hydroxy-camphor amino alcohols, obtained via four-step reaction using the camphor sulfonic acid as starting material, reacted with some aromatic nitriles in the presence of zinc(II) chloride. Nine new camphor-derived single-oxazoline ligands and one camphor-derived bis(oxazoline) ligand were obtained and characterized by IR,1H NMR and13C NMR.