| Summary: | 碩士 === 國立臺灣師範大學 === 化學系 === 98 === In the past decade, acenes have played an important role in the research of organic materials, owing to their excellent photoelectric properties. However, the stability and solubility problems of acenes compounds are formidable roadblocks to their future applications. The goal of this thesis is to develop simple and mild synthetic reaction to synthesis of acene skeletons. Previously, we developed an iterative elongation protocol consisted of Wittig olefination and Knoevenagel condensation. We hereby describe have two new synthetic method based on our published elongation method. Using reagents carrying differentially protected aldehydes, we first carried out a Wittig olefination to extend the length of conjugation yet without the original cyclization. After the protecting groups are removed, the delayed cyclization can furnish the target acene structure without encountering the solubility or stability problems. Second, by employing intramolecular Fries rearrangement as the key step, we are now able to construct a central unit for bidirectional elongation with solubilizing groups attached. The two new strategies greatly improve the current synthetic efficiency. Their applications in the synthesis of bifunctional and bis-chromophoric systems are also discussed.
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