Combination of Reactions and Separations for New Organic Synthesis

有机合成的目的是高效率地生产有用的有机化合物。有机化学家倾向于关注反应的效率和合成策略的能力。然而，重要的是要认识到，合成的总效率也受到分离和离析纯形式产物的能力的限制。尽管已经做出了大量的努力来开发新的有效反应，但是非常有必要开发通常适用于各种结构类型的化合物的战略分离方案。本研究的目的是开发一种新的策略性分离方法和反应的组合，以提高有机合成的能力。我们重点研究了酸碱萃取，发现2-吡啶基二甲基硅基基团可以作为有效的相标记用于此目的。通过氢化硅烷化和与2-吡啶基甲硅烷基甲基锂的反应可以容易地将标签引入有机分子。也可以利用碳代甲烷（Mizoroki-Heck反应）转化为烯基吡啶基硅烷和炔基吡啶基硅烷来合成标记的化合物。通过Tamao氧化和Hiyama交叉偶联反应可以实现标记物的去除。有了标记物，我们已经开发了生物活性化合物如他莫昔芬型四取代烯烃的多样性定向合成。我们还开发了新的方法来构建扩展的π电子系统，它表现出有趣的光致发光等物理性质。利用二官能和三官能卤代芳烃的Mizoroki-Heck反应和交叉偶联反应，合成了具有扩展π电子体系的独特聚合物和树枝状大分子。

The purpose of organic synthesis is to produce useful organic compounds with high efficiency. Organic chemists have tended to focus on the efficiency of reactions and competence of synthetic strategies. It is important to recognize, however, that total efficiency of synthesis is also limited by the ability to separate and isolate products in a pure form. Although substantial efforts have been made to develop new efficient reactions, it is highly necessary to develop strategic separation protocols that are generally applicable for various structural types of compounds. The purpose of this research is developing a new combination of strategic separation protocol and reactions to enhance the ability of organic synthesis.We focused on acid-base extraction and found that 2-pyridyldimethylsilyl group serves as an effective phase tag for this purpose. The introduction of the tag to organic molecules can be easily accomplished by hydrosilylation and the reaction with 2-pyridylsilylmethyllithium. Carbometallation (Mizoroki-Heck reaction) to alkenylpyrilylsilane and alkynylpyridylsilane can also be utilized for the synthesis of tagged compounds. The removal of the tag can be accomplished by Tamao oxidation and Hiyama cross-coupling reaction.With the tag in hand, we have developed diversity oriented synthesis of biologically active compounds such as tamoxifen type tetrasubstituted olefins. We also developed new methods for the construction of extended π-electron systems, which exhibit interesting photophysical properties such as photo luminescence. By using difunctional and trifunctional aryl halides in Mizoroki-Heck reactions and cross-coupling reactions, unique polymers and dendrimers of extended π-electron systems were synthesized.