光控的糖基化反应研究

Sugar chain is the third chain of life after protein and nucleic acid chain. The low availability of sugar chains has been one of the bottlenecks restricting the development of glycoscience. Chemical synthesis is one of the major approaches to obtain the large amount of a uniform sugar chain. General methods are not yet available to construct all glycosidic bonds. The chemical oligosaccharide synthesis is still a challenging problem. The photochemical reactions are arousing organic chemists’ wide interest due to its unique reaction mechanism. Visible light is an abundant, renewable and eco-friendly energy source for chemical reactions. It has found broad utility in organic synthesis recently. Development of efficiently visible light catalyzed glycosylation is not only the need to break the bottleneck of glycoscience, but also the need of the green synthesis of oligosaccharides. Light-mediated glycosylation reaction has been seldom studied and new methods are in urgent demand. The project aims to develop new systems for light-controlled glycosylation of the existing glycosyl donors (such as thioglycosides), and new glycosyl donors with photosensitive leaving group. The enforcement of this project will provide a new and efficient way to the green chemical glycosylation.

糖链是继核酸和蛋白质之后的第三条生命之链。糖链的获取困难一直是制约糖科学发展的瓶颈之一。化学合成是大量得到均一糖链的重要手段。当前，没有一种糖基化方法能普遍适用所有糖苷键的构筑。寡糖的化学合成仍是一个挑战性的难题。光化学反应因其独特的反应历程而引起有机化学家的广泛关注。可见光具有天然丰度大、可再生和环境友好等特点，近几年在有机合成中得到了广泛应用。发展基于可见光的高效糖基化反应不仅是解决糖科学本身的技术瓶颈的需要，而且对寡糖的绿色合成有重要意义。光介导的糖基化方法研究还处于起步阶段。基于可见光的高效糖基化反应体系亟待建立。本项目拟发展针对现有糖基供体（硫苷）的高效光控糖基化反应体系，并发现新的基于光活性离去基的糖基化反应，为寡糖的高效绿色合成提供新的路径。