含雜環芳香Isoxazolines、Isoxazoles與Triazoles的芳杯之合成研究

Abstract

芳杯具有孔洞性結構，為分子辨識領域提供一個非常有用的分子設計平台，將芳杯修飾上多個螯合基團輔助抓取分子是我們所感興趣的研究方向。 本論文已經發展出有效地與高產率的1,3-偶極環化加成方法在芳杯上緣或下緣修飾不同的雜環芳香取代基，所生成的isoxazolines與isoxazoles 62–71可藉由開環反應得到雙官能基化合物，如此一來，芳杯分子不僅具有多個螯合基團，並且可藉由芳香雜環分子的螢光性偵測分子辨識行為。 此外，我們利用雙腈氧化物與上緣單丙烯基取代芳杯進行反應，得到非預期中的特殊分子內架橋芳杯75與分子間架橋芳杯76。由控制實驗顯示，作為溶劑的乙醇會大量消耗腈氧化物，而無法得到與腈氧化物進行親電子取代反應產物。 最後，我們利用相當高產率的click條件在芳杯下緣引入高螢光性的香豆素基團，得到化合物85–88，其螢光量子產率高達0.7。藉由三氮唑與香豆素上雜原子的輔助，預期可用於客體分子的螢光辨識系統。

Calixarenes, which are cavity-containing compounds, are very useful molecular platforms in molecular recognition research. There has been a growing interest in modifying calixarenes with two or more binding sites. We have developed a high yield and convenient method in modifying calixarene with various heterocyclic compounds by 1,3-dipolar cycloaddition reation either on the “lower rim” or on the “upper rim”. The isoxazolines and isoxazoles 62–71 obtained from these reactions are known to be very useful precursors for various bifunctional compounds by ring-opening reactions. Based on this design, the calix[4]arenes not only provide multifunctional chelating sites but also the fluorescence properties from the appended aromatics. Besides, calix[4]arene with a unique structure 75 was obtained by 1,3-dipolar cycloaddition and electrophilic substitution between bis-dipoles and monodipolarophile. Compound 76 was also isolated from this reaction. Using nitrile oxide 61c react with 2,6-dimethlphenol for comparison, no such an electrophile substitution product can be found because nitrile oxide was consumed by ethanol which served as a solvent. Finally, Copper (I) catalyzed 1,3-dipolar cycloaddition reactions of 3-azidocoumarin and calix[4]arene bearing propagyl group afforded mono- and bis-1,2,3-triazole substituted calix[4]arenes 85–88, The carbonyl group on the coumarin and the nitrogen atoms on triazole may play an important part in molecular recognitions.