| Summary: | 博士 === 國立清華大學 === 化學系 === 99 === The synthesis of Dibenzo[g,p]chrysenes and Tetrabenzo[de,hi,mn,qr]naphthacenes bearing various functionalities and their physical properties and development of few new methodologies involving transition metal catalysis are mentioned in this dissertation. For sake of convenience and better understanding, the thesis is divided into four chapters. In the first chapter a new synthetic pathway to functionalized dibenzo[g,p]chrysenes and tetrabenzo[de,hi,mn,qr]naphthacenes from bis(biaryl)acetylenes and from 1,2-di(phenan thren-4-yl)ethynes, respectively, has been described. We also presented the properties of dibenzo[g,p]chrysenes and tetrabenzo[de,hi,mn,qr]naphthacenes their UV absorptions, and fluorescent emissions. The second chapter deals with an unprecedented ruthenium-catalyzed cyclization of 3-en-5-ynyl and O-alkynyl phenyl nitrones to α-pyridones and 3(2H)-isoquinolones, respectively, via formation of ruthenium vinylidene intermediate. A plausible mechanism was proposed on the basis of deuterium-labeling experiments. The third chapter describes, a gold-catalyzed oxidative ring expansion of alkynyl cyclopropanes, this approach introduces regioselectively a new ketone functionality using Ph2SO an external oxygen donor to gave cyclobutenyl ketone and 2H-pyran. The fourth chapter presents a novel silver-catalyzed protocol for the synthesis of carbocycles from β-keto-2,2-dimethyl cyclopropanes via cleavage of a sp3 C-H bond.
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