Study Of Oxazoline Substituted Planar Chiral Carbene Copper Complexes Catalyzed Asymmetric Boration Readions

Asymmetric catalysis has been one of the hot spots in the study of organic chemistry. The synthesis of chiral ligands with excellent activity and selectivity is the key to the success of asymmetric catalysis. Since the first time, the NHC has attracted many researchers’ attention and attention since it was separated for the first time in the world.It is widely applied to various catalytic reactions with its good electronic properties and structure. Chiral elements are introduced into the framework of the nitrogen heterocyclic ring, NHC can be used as chiral ligands for asymetric catalysis of the different reactions。NHC itself can be used in organic catalysis, and if combined with metal it can also be used in organic metal catalysis. The chiral elements not only have the common central chirality, also includes axial chirality、planar chirality、helical chirality. Because of its own advantages as well as the characteristics of planar chirality,the application of [2.2]paracyclophane in asymmetric catalysis have also been reported more and more.Our laboratory has been committed to the combination of planar chiral [2.2] paracyclophane imitation and NHC, the design and synthesis of the a series of planar chiral [2.2] paracyclophane NHC catalysts based on, and transition metal formed complexes were used in a series of asymmetric reactions, and achieved very good results.A series of novel bidentate NHC precursors based on planar chiral [2.2]paracyclophane combined with the central chirality have been synthesized in our group. They are applied successfully in the asymmetric boron borylation of α,β-unsaturated esters. On this basis,we try to further modify the structure of the ligand in order to improve the ee in the asymmetric borylation of α, β-unsaturated estersThe dissertation includes differentl parts as following:1、Review of the chiral imidazolium ligand in asymmetric catalysis and the boration of α, β-unsaturated esters.2、Synthesis of oxazoline substituted planar chiral imidazo pyridinium chlorine salts.3、The study on asymmetric borylation of α, β-unsaturated esters and k etones.The innovation of this paper is as follow:1. Based on the study of our group, the space structure of the ligand were further modified, synthesized a series of oxazoline substituted planar chiral imidazolium salts, and synthesized for the first time imidazo quinoline chlorine salts for the first time.2. Asymmetric reaction of α, β-unsaturated ester catalyzed by novel NHC-Cu ligands was performed, and asymmetric boration of unsaturated ketone catalyzed by NHC was performed.3.The methods and reaction conditions of the synthesis of ligands were optimized. The reaction conditions were more moderate and the yield was improved.