Study On The Construction Of Spirobarbituric Acids And Polycyclic Aromatic Hydrocarbons Based On The Tandem Reaction Of P-QMs

Para-Quinone Methides（p-QMs）is a special kind of cyclohexadienone,which is an important intermediate in organic synthesis and has high application value as a Michael acceptor.Spiropyran and spiro barbiturates are widely used in many biologically active natural products and synthetic compounds.Considering the biological activity of spiro pyran and spiro barbituric acid,we expect that the integration of the two structures into one molecule may lead to a group of new candidate molecules.Polycyclic aromatic hydrocarbons（PAHs）,such as naphthopyran,naphthofuran and fluorenone,have attracted much attention as a research hotspot in recent years,which have been proved to have biological activity.However,the existing synthetic methods have the defects of expensive raw materials and difficult control of reaction conditions,so it is necessary to develop a synthetic method with cheap raw materials,high yield and easy control of reaction conditions.In this study,the spirobarbiturates product was effectively constructed by using Et₃N to catalyze the tandem reaction of p-QMs.With high yield（up to 99%yield）and high diastereoselectivity（>99:1 dr）,we obtained 19spirobarbiturates compounds.In This study,high yield naphthopyran（89-96%yield,10 examples）and fluorenones（86-95%yield,10 examples）were constructed by using metal and base catalyzed oxidative coupling tandem reaction of p-QMs;Naphthofuran（93-99%yield,19 examples）was constructed through the1,6 addition-oxidative dearomatization reaction of p-QMs.