Synthesis Of Heterocyclic And Fused Ring Compounds Containing Phenylethynyl Groups

As a result of nonsaturation and conjugacy of triple bond, aromatic ring compounds containing phenylethynyl groups may be used as high polymer monomer but also as asymmetry diketone raw materials and electroluminescent materials. For synthesis of phenylethynyl substituted compounds, catalytic cross-coupling of phenylacetylene with aryl halides and oxidative addition of metallo organic compouds with carbonyl compounds are two important methodsIn this paper, seven kinds of aromatic ring compounds containing phenylethynyl groups were synthesized by cross-coupling reactions with aryl bromides and phenylacetylene in the presence of Pd(PPh₃)₃Cl₂ (change nitrogen gas protection for nitrogen and hydrogen gaseous mixture protection). The effects of protective gases, solvents, reaction temperature, catalyst and substituted groups upon palladium-catalysed cross-coupling reactions were investigated. The side product of two terminal acetylenes in the Sonogashira reaction can be reduced obviously using atmosphere of hydrogen and nitrogen mixture protection. The side product yield is determined not only by concentration of catalyst and oxygen, but also concentration of phenylacetylene and reaction temperature, the probable mechanism was presented. Moreover, oxidation of the triple bond in 2-phenylethynyl pyridine and 3-phenylethynyl pyridine with potassium permanganate have been carried out to give 1-phenyl-2-(2-pyridyl)1,2-diketone and 1-phenyl-2- (3-pyridyl)1,2-diketone.In this paper, 9,10-anthraquinone, 2-methyl-6,11-diphenyl-5,12-naphthacenequinone and 6,11-diphenyl-5,12-naphthacenequinone reacted with sodium phenylacetylide in dioxane respectively, then without separation, the hydrolyzed products were treated with a solution of stannous chloride in acetic acid to form 9,10-diphenylethynyl anthracene, 2-methyl-6,11-diphenyl-5,12-diphenylethynyl naphthacene and 6,11-diphenyl-5,12-diphenylethynyl naphthacene. Among the target products, 2-methyl-6,11-diphenyl-5,12-diphenylethynyl naphthacene and 6,11-diphenyl-5,12-diphenylethynyl naphthacene are new ones which have not been reported so far. All above-mentioned procedures were monitored by HPLC and TLC. The products were characterized by MS, IR, NMR, UV and FL spectra. The relationships between their structures and ultraviolet and fluorescence properties were discussed...