| Dihydrofuran quinolinones are an important class of heterocyclic compounds,which are widely exist in natural products and have special biological activities.According to existing reports,dihydrofuran quinolinones has antibacterial and antiviral effects.However,the extraction of natural products cannot meet the needs of modern research.Existing methods for synthesizing dihydroquinolinones often use transition metal catalysis,which cannot avoid the emission of metal residues and by-products,so we need to find a simple and efficient method to synthesize dihydrofuran quinolinone.As a kind of clean energy,sunlight has been used to induce organic reactions for a hundred years.In recent years,photosensitizers and photocatalysts have developed rapidly.Under visible light irradiation,photocatalysts can carry out single electron transfer with organic reactants,which can realize the synthesis of complex structure compounds.And with the advocacy of the green chemistry concept,visible light-induced organic reactions have gradually become a hot topic in the field of organic synthesis.Visible light-induced radical addition cyclization method is considered to be one of the most concise and efficient methods to construct oxygen-and containing heterocyclic compounds.For organic reactions catalyzed by metals,it has no metal residues and has the characteristics of green economy.1,n-enyne can be used as a substrate for tandem cyclization because it contains both carbon carbon double bond and carbon carbon triple bond.In this paper,a series of1,7-enynes were designed and synthesized.Using fac-Ir（ppy）3as photocatalyst and ethyl bromodifluoroacetate as free radical source,dihydrofuraquinolinone compounds were obtained in moderate yield by bicyclization under visible light irradiation;The optimal reaction conditions were obtained by screening and optimizing the reaction conditions.On this basis,a variety of dihydrofuran quinolinone derivatives with different substituents were expanded,which proved the universality of the reaction;The hypothesis of possible reaction mechanism was put forward,and free radical capture experiment and fluorescence quenching experiment were designed to verify. |
