Study On Asymmetric Tandem Reaction Of Unsaturated Aldehydes With Bifunctional Organic Catalysts

Asymmetric tandem reaction served as a powerful tool for constructing complex molecules with multiple chiral centers in a single process has a good development prospect,whichplays an increasingly important role in the fields of organic small molecule catalysis.This thesis mainly elaborates the research of bifunctional catalysts in asymmetric tandem reaction,includes the following five parts.The first chapter mainly introduces the development process of asymmetric tandem reaction from two aspects.The first part describes the asymmetric tandem reaction of chiral amine catalyst catalyzed by enamine imine activation mode is introduced.The second part mainly introduces the application of bifunctional catalyst catalysis in asymmetric tandem reaction.In Chapter two,the asymmetric functionalization of the benzylic C-H of heterocyclic aromatic aldehydes is introduced.We adopt the non-covalent catalytic mode to activate the benzylic position of aromatic aldehydes through bifunctional Br?nsted base catalysts to produce dienolate intermediates and react with nitroalkene.Asymmetric ?-functionalization of aldehydesis and efficient asymmetric synthesis of benzothiophene derivatives achieved.The third chapter describes that the asymmetric functionalization of unsaturated aldehydes catalyzed by organic small molecules is a powerful means of constructing carbon-carbon bonds,which has a wide range of applications in organic synthesis.Asymmetric tandem reaction based on hydrogen bond catalysis,activation of aldehyde carbonyl,ketone carbonyl and nitro f unctional groups through hydrogen bonding to promote the reaction,and can effectively synthesize highly active biomolecules,drug molecules,etc.We developed a series of asymmetric tandem reactions between ?,?-unsaturated aldehydes and pyrones using bifunctional Br?nsted base catalysts to synthesize the benzopyran analogs.