Synthesis Of ?-fused Six-membered Phosphacycles Molecules By Intramolecular Phosphorus Free Radical

Incorporaing phosphorus atoms into the polycyclic aromatic hydrocarbons(PAHs)skeleton is an important strategy to adjust their spatial structure and electronic properties.The formation of carbon-phosphorus bonds through free radical reactions has become an significant method for the synthesis of organophosphorus compounds and has been widely applied in the construction of arylphosphorane derivatives and five-membered phosphole ring conjugated systems.At present,the research on six-membered phosphacycles ring compounds has just emerged and only a few synthetic routes were reported which hinderingtheir further development.In this thesis,we explored a facileaccess tosix-membered phosphacycle annulated polyaromatic ring conjugated systems through free radical reactions.In the first Chapter,reports on the synthesis of phosphorus heterocycles through radical process and the synthesis methods and applications of phosphacycles six-membered rings have been summarized in the first and the second section separately.In the second Chapter,a facile synthetic route to phospha-annulated polyaromatic ring system was developed.This protocol provides pracital and simple access to various six-membered phosphacycles from the silver-catalyzed intramolecular dehydrogenative coupling of the arene fused diarylphosphine oxides.Thirteen novel heteroatoms fused ?-conjugted molecules were synthesized from this procedure with their structures confirmed by X-ray structure analyses.Among them,the six-membered phosphacycles ring fused with benzofuran and indole have higher fluorescence quantum yields,reaching 0.85 and 0.81,respectively.The reaction conditions,substrates scope,the optical properties of partial products and the reaction mechanism were investigated in details.In the third chapter,the detailed synthetic procdures of related compounds are described and the important compounds are characted.