The Intramolecular Acylation Reaction Catalyzes The Synthesis Of Dibenzoxeodione And Its Derivatives

Dibenzocycloketones and their derivatives are ubiquitous structural motifs found in natural products,bioactive molecules,and functional materials.The study of dibenzocycloketone derivatives has become a promising field in organic chemistry.In conventional synthetic routes,the post-treatment of the excess Bronsted acid and Lewis acid required for the Friedel-Crafts acylation reaction produces large amounts of waste.Therefore,the development of a mild and environmentally friendly dibenzocycloketone synthesis strategy is of great significance for chemical synthesis.Acrording to the literature,a process route for the synthesis of a dibenzoxahydro-octacyclic ketone and its derivatives was developed.First,phenyl phthalic anhydride and a phenol compound are used as starting materials,and phthalic anhydride is subjected to nucleophilic substitution,esterification and bromination to synthesize ethyl bromide-2-acetylbenzoates in three steps.Next,the compound and the phenol are subjected to etherification condensation and hydrolysis to obtain the key intermediate 2-?2-phenoxyacetyl?benzoic acids compound.Finally,a series of dibenzooxaheterocyclic ketone derivatives were synthesized by intramolecular cyclization of photocatalytic acyl radicals.The optimum reaction conditions for photo-oxidation-reductioncatalyticintramolecularacylationare2-?2-phenoxyacetyl?benzoic acid compounds and 3.0 mol%fac-Ir?ppy?₃ as photocatalyst.2.0 eq.Dimethyl pyrocarbonate?DMDC?was used as an additive,0.5 eq.2,6-lutidine as a base,and N,N-dimethylacetamide was used as a solvent to react at room temperature for 24 hours under visible light irradiation of a blue LED?5W,?max=455 nm?.All the target compounds synthesized were characterized and confirmed by high resolution mass spectrometry,elemental analysis,ultraviolet spectroscopy,¹H-NMR and¹³C-NMR.