Application Of Amino Acid Derived Chiral Ion-Pairs In Asymmetric 1,3-Dipolar Cycloaddition And Strecker Reactions

Enzyme catalysis has been widely studied as a common catalytic method in nature.It works in mild conditions with high catalytic activity and stereospecificity,but its substrate universality is poor.Therefore,designing a new efficient catalyst is a goal for many biological and chemical workers.Starting from the basic unit amino acid of the enzyme,we have developed a new type of organic small molecule catalyst with multiple structures through multi-step chemical reactions.This dissertation mainly focuses on the cycloaddition reaction to construct the chiral pyrrolidine with furanone ring and the asymmetric strecker reaction to construct the trifluoromethyl-containing compound via amino acid-derived catalysts.This dissertation includes three chapters.Chapter 1:The definition of the chiral ion pair and four catalytic patterns was described.Among these four catalytic patterns,we have focused on the quaternary ammonium cation catalysts.Besides,we briefly reviewed the quaternary ammonium cations catalysts about its development and applications in asymmetric synthesis.Secondly,the development and application of organophosphine catalysts were also elaborated.Chapter 2:The 1,3-dipolar cycloaddition reaction of benzofuran derivatives and imino esters has been achieved by using amino acid derived thiourea-quaternary ammonium salt.Under the optimal conditions,the reaction provided the desired products in good yields and high enantioselectivities,it also provides a method for the preparation of benzofuranone derivatives.Chapter 3:The asymmetric strecker reaction of trifluoromethyl ketimines has been developed by using dual-reagent organophosphine catalysts,which offered an expeditious approach to construct a trifluoromethyl-containing chiral compounds.The corresponding products could be obtained in good yields and enantioselectivities.