Synthesis of Advanced Organic Materials with CH Substitution Reactions of Heteroaromatic Compounds

以银（I）硝酸盐和氟化钾为活化剂，噻吩5位上的C-H取代反应得以进行。设计了咪唑、吡咯等含氮杂环化合物分子内CH取代反应的环化前体。环化反应能容易地生成结构复杂的稠氮杂环化合物，而杂环化合物的CH取代反应与端炔的偶联反应相结合，在我们最近开发的新型活化剂的作用下，可以生成2，5-二芳基噻吩和含炔间隔基的2，5-二芳基噻唑。以噻吩在CH键上的连续同偶联为关键反应，合成了结构明确的含2-8个噻吩单元的寡聚噻吩。由于所制备的低聚噻吩在末端噻吩环上具有碳-溴键，因此可以用几个官能团进行进一步的修饰。过渡金属催化的偶联反应提供了进一步官能化的低聚噻吩。

C-H substitution reaction at the 5-position of thiophene was revealed to proceed with silver (I) nitrate and potassium fluoride as an activator. Addition of the activator in 2-5 portions drastically improved the yield of the coupling product.Cyclization precursors of intramolecular CH substitution reactions of nitrogen heteroaromatic compounds such as imidazoles and pyrroles were designed. The cyclization reaction enabled the formation of fused nitrogen heterocycles of complicated structre in a facile manner.In the combination of CH substitution reaction of heteroaromatic compound with coupling reaction of terminal alkynes with novel activators, which we developed recently, allowed the formation of 2, 5-diarylthiophenes and 2, 5-diarylthiazoles with alkyne spacer. Changes of spectroscopic properties of the produced compounds were discussed.With continueous homocoupling of thiophenes at the CH bond as a key reaction, well-defined oligothiophenes bearing 2-8 thiphene units were synthesized. Since the produced oligothiophenes possess carbon-bromine bond at the end thiophene ring, further modification with several functional groups were made possible. A transition metal-catalyzed coupling reaction furnished further functionalized oligothiophenes.