Based On Chiral NHC Catalyzedintromoleculear Benzoin Reaction Tostereoselectivitysynthesis Of Chromanones And Flavanones Skeletons

In recent years,due to its unique properties and the advantage in the catalytic organic reactions,nitrogen heterocyclic carbene(NHC)has attracted more and more attentions of organic chemists.NHC catalyzed Benzoin reaction is a classic example of umpolung and an efficient stratgy to construct the carbon-carbon bonds.Hence,it has been extensively studied.NHC catalyzed asymmetric Benzoin reaction has also been improved.This thesis focuses on the chiral NHC catalyzed intramolecular Benzoin reaction to stereoselectivity synthesis of Chromanones and Flavanones skeletons.Secondly,based on this strategy,preliminary explorations to construct the benzomacrocycloketones have also been investigated.This thesis is mainly divided into the following three parts:1:The presence of NHC and its application progress in the Benzoin reactionThis chapter mainly describes the presence of NHC and the progress of the NHC catalyzed Benzoin reaction.2 : Based on chiral NHC catalyzed intromoleculear Benzoin reaction to stereoselectivity synthesis of Chromanones and Flavanones skeletonsIn this chapter,we mainly introduce the research to construct Chromanones and Flavanones skeletons via a NHC catalyzed intramolecular stereoselectivity Benzoin reaction with high yield and ee value.3:The study on the stereoselectivity synthesis of benzomacrocycloketones by means of chiral NHC catalyzed intromoleculear Benzoin reactionIn this chapter,we mainly introduce the study on the stereoselectivity synthesis of benzomacrocycloketones via a chiral NHC catalyzed intromoleculear Benzoin reaction.After preliminary studies,we did not get any positive result.