Catalytic Asymmetric Dearomatization [4+1] Spiroannulation Of Halogenated Naphthols

From simple and accessible planar aromatic compounds,asymmetric dearomatization is a powerful strategy to directly construct molecules with specific three-dimensional stereostructures.Among the various reactions,the asymmetric dearomatization of phenols has attracted great attention due to its convenience to directly construct pharmaceutical and biological active cyclohexanedione skeletons.In terms of functional groups,considerable progress has been made in the study of phenols' asymmetric dearomatization strategies recent years,which greatly enriched its application scope.However,the research of phenols scope is relatively lagged behind.On the basis of summarizing the development of phenolic asymmetric dearomatization,the application of halogenated naphthols in asymmetric dearomatization was studied.Here in,we developed a novel [4+1] spiroannulation strategy of halogenated naphthols making a convenient way to pyrazole-containing spirocyclic architechtures.The detailed contents can be divided into the following two chapters:In the first chapter,classified by reactions modes,the oxidative and non-oxidative asymmetric dearomatization studies of phenols are summarized.In oxidative version,the reactions involving chiral iodine reagents and metal reagents are introduced respectively.Non-oxidative dearomatization reactions are mainly introduced from the perspective of functional groups,including alkylation,arylation,allylation,alkenylation,halogenation and amination.In the second chapter,copper-catalyzed [4+1] spirocyclization of halogenated naphthols with 1,2-diazo-1,3-butadiene electrophiles was introduced,and a series of pyrazole-containing spirocyclic structures were obtained.Using chiral Cu(II)/Box catalysts,the asymmetric version was executed with high levels of enantioselectivities(up to 98% ee).It is noteworthy that in the derivatization part,we proposed a naphthol double dearomatization strategy,which would provide a new route for the application of naphthol dearomatization studies.