Metal Or Organic Molecular Co-catalyzed Asymmetric Tandem Reaction For Construction Of Chiral Spirooxindolyl And Ketal Skeleton Compounds

By the use of chiral Takemoto-thiourea bifunctional catalyst or chiral(Box)/Cu(II)catalyst,this thesis focused on asymmetric Micheal addition-initiated tandem reaction between different nucleophiles and salicylaldehyde-derived ?,?-unsaturated ?-ketoesters.The synthetic strategy in this thesis provides a new approach to optically active chiral spirooxindoles derivatives and ketal skeleton compounds.In the first part of the thesis,a consecutive Takemoto-thiourea catalyzed Michael-hemiketalization reaction and sequential co-catalyst mediated intramolecular oxa-Pictet-Spengler reaction provided an efficient process for construction bridged and spiro heterocyclic skeletons in high yields with excellent enantioselectivities.The second part of the thesis,an efficient cascade asymmetric Michael–double-Friedel–Crafts reaction of three components has been developed in the presence of a chiral Takemoto-thiourea catalyst and Lewis acid.A series of enantiomerically enriched spirocyclic indole derivatives have been constructed in high yields with excellent enantioselectivities and diastereoselectivities.The third part of this thesis,asymmetric tandem Michael-ketalization reaction between pyrazolones and salicylaldehyde-derived ?,?-unsaturated ?-ketoesters has been studied.Consecutive(Box)/Cu(II)catalyzed Michael reaction and sequential Br?nsted acid mediated intramolecular ketalization reaction provided an efficient process for construction chairl ketal skeleton heterocyclic compounds.