Synthesis Of Chiral Lactones Based On Indole Ring Skeleton Catalyzed By Nitrogen Heterocyclic Carbene

Asymmetric catalysis realized by organic small molecule catalysts is a research hotspot in the field of catalysis in recent years.Due to its unique advantages,such as: mild reaction conditions,simple post-treatment,non-toxic,stable,efficient,good stereoselectivity,etc,it has received extensive attention from researchers and conducted in-depth research,and has made great progress.So far,more catalytic activation modes have been achieved by organic small molecule catalysts,Such as: enamine catalytic activation mode,imine catalytic activation mode,hydrogen bond catalytic activation mode,phase transfer catalytic activation mode and nitrogen heterocyclic carbene(NHC)catalytic activation mode,etc.The NHC catalysis as a newcomer in the field of organic small molecule catalysis,has been widely used in the efficient construction of C-C bonds and C-X(X = O,S,N)after nearly two decades of vigorous development.However,The efficient construction of ruthenium-based chiral lactones has always been a research hotspot in the field of organic synthesis,Therefore,the NHC catalyzed activation of cyclopropanyl aldehyde to polarity inversion in this thesis,and the chiral lactone of the anthracene ring skeleton was rapidly constructed in one step.This paper mainly describes the contents of two parts:The first part is about the development of nitrogen heterocyclic carbene in the past years,And various novel catalytic activation modes achieved under the catalysis of a nitrogen heterocyclic carbene catalytic precursor,especially stereoselective control achieved under catalytic activation.The second part is the use of nitrogen heterocyclic carbene as catalyst,Catalytic activation of cyclopropanyl aldehydes to polarity inversion and one step to efficiently construct chiral lactones of anthracene ring skeleton,The optimal conditions were determined by screening various conditions(such as catalyst,base,solvent,etc.),and the universality of the substrate was explored based on the optimal conditions.