Studies On Palladium-Catalyzed Asymmetric Allylic Alkylation With Conjugated Dienes As The Atom-Economic Precursors

Asymmetric Allylic Alkylation(AAA)has been developed into an efficient method for constructing carbon-carbon bonds(C-C)in organic synthesis.In traditional asymmetric allylic alkylation,all allylic precursors have a leaving group,which could achieve asymmetric catalytic control by using various chiral ligands and transition metal catalysts,However,such allylic precursors will deliver corresponding byproducts formed from the leaving group lead to low atom-economy.In recent years,unsaturated hydrocarbons including alkynes,allenes and dienes as atom-economy allylic precursors have been widely used to different types of allylation reactions,which impressively improve the atom-economy of the reactions,while further broadening the application of the reaction.However,the types of asymmetric allylation reactions using unsaturated hydrocarbons as allylic precursors are still limited.Exploring new catalyst systems still has great development prospects and value in synthesis.Based on these components,this thesis introduced an asymmetric allylic alkylation of 1,3-dienes with oxazolone pre-nucleophiles by palladium catalyst Pd(?).In addition to the high atomic economy,the reaction can give highly stereoselective 1,2-addition products in the presence of the chiral bidentate phosphine ligand SEGPHOS.Some transformation experiments for products were carried out,and amino acid derivatives with highly optical pure ?-quaternary center could be obtained with good yields.These demonstrate the potential application value of the reaction in the synthesis of active molecules and drugs.In the other hand,under the similar catalytic system,using 1,3-butadiene as allyl sources,1,4-addition products could be obtained in good yield.The scope of substrate is wide.