单线态氧与呋喃类化合物的[4+2]环加成反应研究

There is rich resources of furan derivaetives in Hexi area of Gansu province. Using local furfural as raw materials, the applicant will prepare a series of furan derivatives and investigate sysmatically the [4+2] cycloaddition of different 2-substituent furan derivatives with singlet oxygen for searching the limit and scope of [4+2] cycloaddtion. Its probable mechanism will be suggested. By studying optimum ring-opening conditions of [4 + 2] cycloaddition product, we are intended to obtain the compounds which have biological activity and to explore the relationship between the structure and activity. This [4+2] cycloaddition is green and friendly to environment.To find an effective route for utilizing the [4+2] cycloaddition of furan derivatives with singlet oxygene, we design a reasonable plan for synthesizing natural product, 5-aminolevulinic acid, which has better biological activity and a hoping applied prospect. This project has the typical regional features. It not only has important academic value in theory, but also has a broad prospect of application in practice. It will provide technology support for local economic development.

甘肃省河西地区有丰富的呋喃衍生物资源，申请者拟以本地糠醛为原料，制备一系列呋喃衍生物，系统地考察不同2-取代基的呋喃与单线态氧进行[4+2]环加成反应的限度和范围；并探索[4+2]环加成反应的最佳反应条件，提出合理的反应机理。研究[4+2]环加成产物的开环条件，得到有生理活性的产物，并探索结构与活性之间的关系。应用单线态氧与呋喃的[4+2]环加成反应，合成有生理药物活性的天然有机化合物。该项目绿色环保，具有典型的地区特色，不仅在理论上具有重要的学术价值，而且在实践中上具有广泛的应用前景，能够为地区经济建设发展提供科技支撑。

氧分子有顺磁性，证明其分子中有自旋平行的两个电子，占居最外层两个不同的轨道，当O2 吸收光能后，激发成单线态氧1O2。单线态氧中，外层两个电子占据了同一轨道而自旋方向相反。由于单线态氧具有空轨道， 因此它有强亲电子性, 能参与许多不饱和键(具有相对高的电子密度)反应，破坏不饱和键。单线态氧在生物体中广泛存在，并具有复杂而有趣的化学性质。本项目利用当地丰富的资源糠醛为原料，合成了一系列糠醛的衍生物，研究呋喃环与单线态氧【4+2】的环加成反应，对其反应条件如底物结构、溶剂、温度、波长进行了探索,提出了一个涉及DaLamare 重排的可能反应机理。同时，在合成糠醛衍生物的过程中，研究发现了几种非均相催化剂，对催化剂进行了合成和表征，并研究了其对缩合反应、Suzuki–Miyaura偶联反应、Heck反应等的催化性能。