The Asymmetric Construction Of Nitrogen-Containing Heterocyclic Ring System Catalyzed By Secondary Amine

Nitrogen-containing heterocyclic skeleton is widely exsiting in natural products and biologically significant compounds,has a wide range of applications in medicine,agriculture,organic synthesis and other related research fields.So many efforts have been made to construct chiral nitrogen-containing heterocyclic derivatives.This dissertation mainly focuses on the construction of the nitrogen-containing heterocyclic skeleton by organic catalyst.The dissertation include two parts as follows:1.Asymmetric construction the piperidine derivatives via[3+3]cycloaddition reaction ofacyclic ketimine and ?,?-unsaturated aldehydes catalyzed by secondary amine.In this part,asymmetric[3+3]cycloaddition of acyclic ketimines and ?,?-unsaturated aldehydes catalyzed by diarylprolinol silyl ethers under base condition was developed,affording piperidinone derivatives in good yield(up to 82%)and excellent enantioselectivities(up to 99%).The corresponding cycloaddition products were also submitted to Friedel-Crafts alkylation of indole to give the indolyl substituted chiral piperidine derivatives in good yield(up to 68%)and excellent diastereoselectivities(>20:1)without loss of ee values.2.The synthesis of noval chiral dispiropyrrolidine skeleton catalysts and their preliminaryapplication in asymmetric catalysis.A series of novel chiral secondary amine catalysts based on dispiropyrrolidine skeleton were designed and one of them were synthesized from 3,5-bis-(1,1-dimethylethyl)-2-hydroxy-benzaldehyde over 6 steps via asymmetric 1,3-dipolar cycloaddition catalyzed by a chiral N,O-ligand/Cu(OAc)2 system.The catalysts were preliminarily applied to catalyze the reactions of phenylpropiolaldehyde.