Study On Visible-Light-Promoted Decarboxylative Radical Addition/Tandem Cyclization Reaction

In recent years,visible light promoted photochemical reactions have made great progress.Visible light is a cheap,clean and relatively mild renewable energy.Therefore,using visible light catalysis to synthesize complex molecules has a good prospect.In addition,nitrogen-containing heterocyclic compounds widely exist in natural products and drug molecules and are widely used as building block in organic synthesis.Therefore,we construct nitrogen-containing heterocyclic compounds from easily available starting materials via the conditions of a visible light-promoted.In this thesis,the visible light-promoted decarboxylation/acylation/ cyclization cascade of ?-keto acid was investigated to synthesize acyl-substituted isoquinoline-1,3(2H,4H)-diketones.Meanwhile,the visible light-promoted decarboxylative methylation/tandem cyclization with iodobenzene acetate was also studied to prepare a series of 3,4-dihydroquinoline-2(1H)-ones.Chapter one: ?-keto acid decarboxylative acylation reactionsIn this chapter,the decarboxylation and acylation of ?-keto acid was described.Different substrates,such as aryl compounds,unsaturated hydrocarbon compounds and heteroatom-containing compounds were employed in these acylation reactions.Chapter two: Visible-Light-Promoted Acyl Radical Cascade Reaction for Accessing Acylated Isoquinoline-1,3(2H,4H)-dione DerivativesIn this chapter,a visible-light-promoted decarboxylative acyl radical acylation/cyclization cascade reaction of N-methacryloylbenzamides with ?-keto acid for accessing acylated isoquinoline-1,3(2H,4H)-dione derivatives was described.This protocol features mild reaction conditions,operational practicality and a broad substrate scope.The introduction of acyl groups and the construction of fused heterocycles took place in one efficient step.Chapter three: Visible-Light-Promoted methyl Radical Cascade Reaction for Constructing 3,4-Dihydroquinolin-2(1H)-onesIn this chapter,a visible-light-promoted decarboxylation/methyl radical addition/cyclization reaction cascade was researched.In this investigation,iodobenzene acetate was used to form methyl racical via the visible light-promoted decarboxylation and a series of methylated 3,4-dihydroquinoline-2(1H)-ones weresynthesized.The method highlighted mild reaction conditions,simple and practical operation and good substrate applicability.