三联五元杂环具有特殊的光电特性和生物活性等，被广泛地应用于有机光电材料、医药等研究领域。因此，高效合成三联五元杂环及其应用推广一直是有机合成化学和药物化学研究的重要内容之一。本论文工作主要包括：（1）设计和优化路线合成了一系列三联五元杂环化合物（包括2,5-Bis(5-hydroxymethylthien-2 -yl)furan，RITA），并探讨了RITA及其他三联五元杂环的结构与体外抗肿瘤细胞增殖活性之间的关系；（2）利用三联噻吩等五元杂环修饰PPE-CO2H的骨架合成一系列共轭聚电解质PTs-CO2H，并应用于细胞色素C的荧光淬灭实验。 本论文首先通过Sonogashira偶联、Glaser偶联反应合成一系列1, 4-二（五元杂环）-1, 3-丁二炔衍生物，然后在强碱体系KOH/DMSO下优化1, 4-二（五元杂环）-1, 3-丁二炔与H2O、Na2S?9H2O的环化加成反应，建立了合成RITA及其一系列类似物的高效新合成方法。MTT（四唑盐比色法）实验结果表明，RITA类似物的取代基结构、杂原子种类和数量均对抗肿瘤细胞增殖活性具有较大影响。2,5- Bis(5- hydroxy-methylthien-2-yl)thiophene对所选择的4种癌细胞系（人白血病细胞系K562、人乳腺癌细胞系MCF-7、人肺癌细胞系A549和人结肠癌细胞系HCT116）均显示出比RITA更高的抗肿瘤细胞增殖活性，其中对K562的半抑制浓度（Half Maximal inhibitory concentration，IC50）分别是0.523 μM，1.133 μM，说明2,5-Bis(5- hydroxymethylthien-2-yl)thiophene的三联噻吩骨架比RITA的2, 5-二噻吩取代呋喃骨架更有助于抑制肿瘤细胞增殖活性，而2,5-Bis[5-(2-methyl-1,3-dioxolan-2-yl) thiophen- 2-yl]thiophene对MCF-7、A549和HCT116具有最高的活性，说明2,5-Bis [5-(2-methyl-1,3-dioxolan-2-yl)thiophen-2-yl]thiophene的2-甲基-1,3二氧戊环取代基能有效抑制肿瘤细胞增殖活性。 本论文工作进一步将三联噻吩等五元杂环修饰到PPE-CO2H主链骨架，并用光谱仪器表征含五元杂环的聚合物PTs-CO2H。合成的化合物溶液的紫外-可见光吸收和荧光研究表明，三联噻吩修饰得到的PT3-CO2H比未修饰的PPE-CO2H显示出更大的红移和更强的荧光强度（其中最大发射波长λmaxem在CH3OH和H2O的红移分别是46 nm和48 nm）；而且PT3-CO2H对溶剂极性变化非常敏感。荧光淬灭实验表明，PT3-CO2H能够在纯水和碱性溶液中有效地被低浓度细胞色素C淬灭，可以将PT3-CO2H应用于细胞色素C的检测。

Five-membered triheterocyclic compounds have been widely applied for organic optoelectronic materials, medicines and other fields because of their unique optical properties and biological activities. Therefore the synthesis and application of five-membered triheterocyclics have also been one of the important research topics in organic synthetic chemistry and medicinal chemistry. The research work in this dissertation includes: (1) a series of five-member triheterocyclic compounds (including RITA: 2,5-bis(5-hydroxymethylthien-2-yl)furan) were synthesized efficiently via optimizing synthetic ways, and the relationship between antitumor activities and the structural properties of heterocyclics was also discussed. (2) a series of conjugated polyelectrolyte PTs-CO2H were prepared by the modification of PPE-CO2H via the introduction of five-membered triheterocyclics into the skeleton, and the fluorescence quenching experiment for cytochrome cwas also studied. The syntheses of RITA and its analogues were performed by the cycloaddition reactions of 1,4-bis(five-membered-triheterocyclics)-1,3-butadiynes with H2O or Na2S.9H2O under the strong base of KOH/DMSO conditions, and 1,4-bis(five- membered-triheterocyclics)-1,3-butadiynes was prepared by Sonogashira coupling and Glaser coupling reactions. The studies of MTT disclosed that the antitumor activities of five-membered triheterecyclics depended greatly on the kinds of heteroatoms and their numbers, as well as the properties of substituents. On the basis of the studies of antitumor activitities in K562, MCF-7, A549 and HCT116, it has been found that 2,5-bis(5-hydroxymethylthien-2-yl)thiophene shows a higher antitumor activity than RITA (IC50 is 0.523 μM and 1.133μM for K562 cell, respectively), indicating that terthiophene skeleton of 2,5-bis(5-hydroxymethylthien-2-yl)thiophene is efficiently to improve the antitumor activity. In addition, 2,5-bis[5-(2-methyl-1,3-dioxolan-2-yl)- thiophen-2-yl]thiophene has the highest antitumor activity for MCF-7, A549 and HCT116 cells, disclosing that 2-methyl-1,3-dioxolane moiety in 2,5-bis[5-(2-methyl- 1,3-dioxolan-2-yl)thiophen-2-yl]-thiophene is a key factor to improve the antitumor activity compared with othe substituents. The syntheses of a series of PTs-CO2H was by introducing triheterocyclic groups into the skeleton of PPE-CO2H, and the studies of UV and fluorescence in solution disclosed that PT3-CO2H with terthiophene moiety in skeleton showed obviously red shift and stronger fluorescence than PPE-CO2H. The red shift of maximum fluorescence emission wavelength in CH3OH and H2O are 46 nm and 48 nm, respectively, and also PT3-CO2H shows the most sensitive to the polarity of solvents. The results of fluorescence quenching experiment (substance is cytochrome c) showed that PT3-CO2H could effectively quenched by the lower concentration of cytochrome c in deionied water and alkaline water solution, so as to achieve the detection of cytochrome c.