Chiral Ion-pairing Catalysts Derived From Amino Acid And Application To The Asymmetric Cycloaddition Reactions

The structure diversity and complexity of natural compounds have inspired chemists to develop simple and efficient synthetic strategies to construct these compounds.In particular,the spiro-oxindoles and the indolines with a fused five-membered ring at C₂ and C₃ positions represent key structural motif of a number of natural products which exhibit a wide range of biological activities.Thus,developing new,highly enantioselective methods for the direct construction of these skeleton is very important.Aside from transition-metal catalysis and enzyme catalysis,asymmetric organocatalysis have become a powerful strategy for construction of chiral molecules.The well-developed organocatalysis patterns including enamine and iminium catalysis,nucleophilic catalysis,hydrogen bonding catalysis,N-heterocyclic carbene?NHC?catalysis and ion-pairing catalysis.The ion-pairing catalysis which has become a powerful and versatile methodology for the asymmetric synthesis.This dissertation mainly focused on asymmetric cycloaddition reactions catalyzed by amino acids-derived cation-directed catalysis to construct the skeletons of the spiro-oxindoles and the indolines with a fused five-membered ring.In chapter 1,asymmetric ion-pairing catalysis was reviewed according to different catalyst patterns.In chapter 2,the enantioselective construction of five-membered spirocyclic oxindoles via a double Michael cascade reaction is described by using dipeptide-based multifunctional quaternary phosphonium salt catalysts.The desired products were obtained in excellent yields and good to high stereoselectivities.In chapter 3,a highly enantioselective 1,3-dipolar cycloaddition of imino esters with methyleneindolinones has been realized by using readily available thiourea-quaternary ammonium salts as phase-transfer catalysts,enabling efficient construction of a range of chiral spiro[pyrrolidin-3,3?-oxindoles]in good yields with excellent enantioselectivities under mild conditions.In chapter 4,a[3+2]cycloaddition reaction of 3-NO₂ indoles is described by using dipeptide-based multifunctional quaternary phosphonium salt catalysts to construct the indolines with a fused five-membered ring.The desired products were obtained in moderate diastereoselectivities and enantioselectivities under mild conditions.