| Summary: | 博士 === 國立清華大學 === 化學系 === 94 === The thesis describes dipolar and nickel-catalyzed organic synthesis leading to coupling and cyclization of heterocyclic compounds. It is subdivided into four topics in four chapters. The first chapter describes nickel-catalyzed cyclization of aryne precursors with allene and diyne derivatives resulting in the formation of 9,10-dihydrophenanthrene and naphthalene derivatives in moderate to excellent yields. The second chapter extends the aryne precursors to precede 1,3-dipolar cycloaddition and coupling reaction with azide and isocyanate derivatives to form benzotriazole and diphenylamine derivatives in good to excellent yields. The third chapter deals with reaction of isocyanates with β-iodobenzoate and halobenzene derivatives to form imides and amides. The fourth chapter consists of cycloaddition of 1,2-dihalidearenes with alkynes and diynes to form 1,2,3,4-tetrasubstituted naphthalene derivatives.
The first chapter describes the nickel-catalyzed cycloaddition of arynes with allenes and diynes. The arynes could be proceeded cycloaddition with allenes and diynes in the presence of Ni(dppe)Br2, zinc powder and cesium fluoride in acetonitrile at 80 oC to afford the corresponding phenanthrene and naphthalene derivatives in moderate to excellent yields. The phenanthrene derivatives give high regio-, stereo- and chemo selectivity; in contract the naphthalene derivatives afford excellent functional group and fused ring size tolerance. The mechanism of these two reactions is through the intermediate of nickelacyclopentadiene by Ni(0) complex with two molecules of triple bonds, followed by insertion of another one and reductive elimination to form the corresponding products.
The second chapter describes the coupling reaction of arynes with azides and isocyanates. The arynes undergo the 1,3-dipolar cycloaddition with azides to form the 1H-benzo[d][1,2,3]triazole derivatives in good to excellent yields with high functional groups tolerance. The arynes could also precede the very unique fluoride promoted coupling reaction with isocyanates in moderate to good yields.
The third chapter describes the nickel-catalyzed cycloaddition and coupling reaction of isocyanates with β-iodiesters and arylhalide. In the presence of NiBr2(dppe), additional dppe and zinc powder in acetonitrile at 80 oC, the coupling reaction of isocyanates with β-iodiesters and arylhalide could be succeed to proceed and afford the corresponding imide and amide derivatives in moderate to excellent yields. The reaction of forming imides shows the excellent functional group tolerance, however, the reaction of forming amides reveals the lower yields with limited cases.
The fourth chapter describes the nickel-catalyzed cycloaddition of 1,2-dihaloarenes with alkynes and diynes. The 1,2-dihaloarenes undergo cycloaddition with alkynes and diynes in the presence of Ni(dppe)Br2, additional dppe and zinc powder in acetonitrile at 100 oC to afford the corresponding 1,2,3,4-tetra substituted naphthalene products in moderate to excellent yields. Variou alkynes and diynes react with 1,2-dihaloarene derivatives to give good functional group tolerance. The mechanism is proposed by the oxidative addition first, then insertion of a triple bond and coupling with another carbon-halide bond to form the intermediate of nickelacyclobenzopentene. Finally, another triple inserts to the nickel complex and proceeds reductive elimination to afford the corresponding naphthalene products.
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