| The thesis consists of three chapters as follows:Chapter one: The recent development in asymmetric Diels-Alderreaction catalyzed by different types of chiral complexes.Recent progresses in asymmetric Diels-Alder reactions are intruduced accordingto the types of chiral complexes.Chapter two: Synthesis of New Chiral Mono(oxazoline) Ligandsand their Application in Asymmetric Diels-Alder Reaction1. Three new chiral ligands of C-1symmetric monoxazoline were synthesized.Transamidation of the commercially available diethyl isophthalic acid with excessiveCH3OH under acid conditions led to dimethyl isophthalate，which was then reactedwith aminoalcohols under reflux conditions to give monoamide. Monoxazoline wasobtained by TsCl/Et3N cyclization of monoamide. The desired chiral ligands1e,1f,1gcould be prepared directly by the reaction of monoxazolines with2equivalent ofGrignard reagents.2. Asymmetric Diels-Alder reaction catalyzed by new monooxzoline ligands wasstudied. Reaction of3-acryloyloxazolidin-2-one with cyclopenta-1,3-diene in thepresence of5mol%monooxazoline ligands1b-Pd(PPh3)2Cl2complex at-45oC wasexplored to give3-(bicyclo[2.2.1]hept-2-enecarbonyl)oxazolidin-2-one with98%good yields and with99%good endo/exo. Enantiomeric excesses is also up to99%.Chapter three: A new method for the synthesis of Pybox.This chapter described a new method for the synthesis of Pybox, which was obtained bypyridine-2,6-dicarboxylate taking three steps. Reacted with different chiral amino alcohols,pyridine-2,6-dicarboxylate was converted to bisamides. Pybox was obtained byTsCl/Et3N cyclization of monoamide. |
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