Synthesis Of 1,2 - Di - Substituted Acenaphthylene By Non - Terminal Alkynes Participating In Palladium - Catalyzed Coupling Reaction

Acenaphthylene skeleton is an elementary subunit which was commonly incorporated in cyclopentene-fused polycyclic aromatic hydrocarbons(CPAHs), since its structure is very similar to the fullerenes, and has wide applications in organic photovoltaic material, the synthesis and study of derivatives of acenaphthylene aroused great interest in synthetic organic chemists.1,2-Disubstituted acenaphthylene derivatives have been successfully applied to further synthesize thiazole-fused, furan-fused, thiophene-fused, pyridine-fused and other polycyclic heteroaromatic hydrocarbons. However, the synthesis of1,2-di-substituted acenaphthylene mainly through organic synthesis reagents and their equivalents bimetallic reagent such as di-B, platinacycles and nickelacycle by double coupling tandem reaction in palladium-catalyzed. The bimetallic reagents have many shortcomings, such as high prices, low yield synthesis, easy to cause environmental pollution and metal waste and poor functional group tolerance. Thus, the development of a new, not using organometallic reagents, simple and efficient synthesis of1,2-disubstituted acenaphthylene approach has important theoretical and practical significance.In1993, Dyker reported a palladium-catalyzed annulation procedure of1,8-diiodonaphthalene and substituted alkynes for the synthesis of1,2-disubstituted acenaphthylene derivative, but the yield is low which is mainly due to1,8-diiodonaphthyl Ullmann reaction caused by its own. Dyker found that an excess of the alkyne (10eq.) can get a moderate yield. However, the use of a large number of alkyne greatly limits the application of the synthesis method. Based on thoes results, in this paper, the moderate reactivity and easily synthesized dibromo reagent were used to prepare the1,2-disubstituted acenaphthylene derivative catalyzed by palladium catalyst through coupling of the tandem cyclization reaction.1,8-dibromo-naphthyl,5,6-dibromo acenaphthene and diaryl acetylene, aryl/alkyl dialkyl acetylene and acetylene were used in this process and get1,2-disubstituted acenaphthylene derivative in higher yields (the maxium yield up to83%). The reaction only requires1.2eq. alkyne derivatives. This process effectively inhibits the side catalytic reaction Ullmann coupling reaction of an aryl bromide. Chloride diaryl acetylene also gives high yields of cyclic compounds.1,2-Dichloro-substituted aryl acenaphthylene produced by the above process can further synthesized PAH dibenzo[j,l]fluoranthene by self-Ullmann coupling reaction. The thesis comprises three chapters.The first chapter introduces the mechanism, the synthetic applications and the latest developments of Sonogashira coupling and Ullmann reaction; the coupling and cyclization reactions which involve alkyne and its latest developments; the Synthesis of current research of1,2-disubstituted acenaphthylene and the thesis’s purpose and meaning.The second chapter, based on Sonogashira coupling,8kinds of non-terminal alkynes has been synthesized, at the same time, through a multi-step reaction we successfully got the1,8-dibromonaphthalene and5,6-dibromo acenaphthene.In chapter3, we take1,8-dibromonaphthalene reaction with diphenyl acetylene as templates, select the optimal reaction conditions. On this basis, using1,8-dibromo-naphthalene and5,6-dibromo acenaphthene as the substrate with a number of aryl/aryl-substituted acetylene, aryl/alkyl-substituted acetylene and alkyl/alkyl-substituted acetylene generate16kinds of1,2-diaryl-,1,2-aryl-/alkyl-and1,2-dialkyl substituted acenaphthylene in moderate to good yields. All products are consistent with the expected structure through the full characterization.