Study On Bifunctional Catalysis&Lewis Acid/Visible Light Cooperative Catalysis Based On Metal-Centered Chirality

Bifunctional catalysis and cooperative catalysis represent methods which combine different activation modes of the substrate in asymmetric catalysis.It's one of the most efficient way to construct chiral C-C and C-X bond.These two strategies play very important roles in asymmetric organic transformations,particular in multi-chiral center and challenging bonds.However,it was poorly reported transition metal involved bifunctional catalysis and cooperative catalysis system.It can be reasoned by the limitation of different catalyst's suitability and substrate's reactivity.Based on this point,we design and synthesis some new bifunctional catalysts.The new bifunctional catalysts can been used in the challenging C-C bond construction.In addition,combine chiral transition metal Lewis acid catalyst with visible light photoredox eatalyst in Cooperative catalysis system to construct chiral C-N bond gives a new thought to green asymmetric transformation.In Chapter 1,the application and research progress of transition metal involved bifunctional catalysis and cooperative catalysis.In Chapter 2,is the research work 1:First of all,we select uracil-containing compound as our bis-cyclometalated ligand of Iridium(?)complex.Secondly,we synthesize chiral bifunctional catalysts though an auxiliary mediated strategy.The absolute configuration of bifunctional catalyst is determined by single crystal diffraction and the enantiomeric excess(>99%ee)is determined by chiral HPLC analysis.Then,we make a detailed test of the catalyst's catalytic activity.We are delight to find it's excellent catalytic activity in Indole C2 alkylation.It is noteblely that the previous reported single functional Lewis acid catalyst can not catalyze this reaction in an efficient way,due to low nucleophilicity of Indole C2 position.And the stereocontrol is more difficult.Compared with single functional catalyst,bifunctional catalyst's functional group Uracil plays vital role in both product formation and asymmetric induction.In Chapter 3,is the research work 2:Application of combining chiral rhodium Lewis acid and visible light photoredox catalyst in cooperative catalysis system.We introduce a novel strategy to establish a new C-N bond in ?-position of an?,?-unsaturated carbonyl compound in a catalytic,enantioselective fashion.We proposed the mechanism via photoinduced proton-coupled electron transfer,followed by a highly stereoselective radical-radical recombination controlled by a chiral rhodium-enolate radical intermediate by the result of different control experiments.This mechanistic strategy opens new avenue for the catalytic,enantioselective synthesis of chiral amines.In Chapter 4,the summary and outlook are presented.