Synthesis Of Trifluoromethyl Substituted Tetrahydroquinolines Catalyzed By Chiral Phosphoric Acids Via Asymmetric Povarov Reaction

Chiral phosphoric acids as an important organic small molecular catalysts havegood catalytic activity and chiral induce effect, and they have been extensivelyapplied in the field of asymmetric catalytic. Chiral phosphoric acid catalyzedasymmetric Povarov reaction is the most concise and effective method for buildingtetrahydroquinoline skeleton and preparing chiral tetrahydroquinoline derivatives.On other hand, organofluorine compounds have received extensive attentions inthe area of pharmaceutical industry, agrochemistry and materials science due to theirunique chemical, physical and biological properties. Hence, developing moreeffective strategies to prepare organofluorine compounds is of considerableimportant and still in great demands.This thesis mainly studies chiral phosphoric acid catalyzed asymmetric Povarovreaction of trifluoromethyl imine’s to prepare tetrahydroquinoline derivatives, ofwhich C2position was substituted by trifluoromethyl group.The paper consists of three parts:The first chapter: Research Progress in Asymmetric Povarov ReactionIn this chapter, a brief introduction to the Povarov reaction was given. Accordingto the different kinds of catalysts used in asymmetric Povarov reaction, this chapterdetailed from two aspects: The first aspect, chiral metal complex catalyzedasymmetric Povarov reaction; The second aspect, small organic molecules catalyzedasymmetric Povarov reaction.The second chapter： Synthesis of Trifluoromethyl SubstitutedTetrahydroquinolines Catalyzed by Chiral Phosphoric Acids via AsymmetricPovarov ReactionIn this chapter, trifluoromethyl imine and2,3-Dihydrofuran were exposed in chiralthiourea, chiral metal complex to undergo asymmetric Povarov reaction. However,racemic the tetrahydroquinoline was provided. When using (R)-BINOL derived N-triflyphosphoramide5c as catalyst, the tetrahydroquinoline was obtained in80%yield, cis/trans75/25and cis32%ee, trans60%ee. The properties of thistransformation were increased to98%yield,97/3dr and97%ee wheno-hydroxystyrene was used as substrate, and (R)-BINOL derived chiral phosphoricacid4d and4g were used as catalyst.The third chapter: Study on the Synthesis of Carboxylic Esters Promoted byPCl3In this chapter, the preparation of carboxylic esters in the presence of PCl3inone-pot was investigated. The method has the advantages of mild reaction conditions,simple operation, good yields and simple synthesis procedure to prepare carboxylicesters.