A Traceless Approach For The Synthesis Of 3,5-Disubstituted Thiohydantoins On Functionalized Ionic Liquid Support

Ionic liquids (ILs), recognized as a novel class of solvents since last decade, have attracted more fundamental interest as green reaction media. These potential solvents have many especial and fascinating properties such as low vapor, high thermal and chemical stability, easy separation from many organic solvents and high loading capacity.Recently, the illustration of ionic-liquid-supported synthesis (ILSS) have been drawing more and more attention. When ionic liquid support was prepared, the first reactant is anchored onto it completely, the excess reagents and byproducts could be removed by simple solvent washing. Then, the second and the third reagents can also be linked by the same way. The substrates anchored on ionic liquid would be cleavaged by different regent effectively. Previous reports have illustrated the efficiency of ILSS for small molecules, enkephalin and oligosaccharide, including some enzymatic reactions can be carried out on ionic liquid. The available of recyclable and recoverable ionic-liquid-supported catalysts have also been explored. In addition to those properties, they are also readily prepared from commercially available reagents and recycled conveniently in most cases.The dissertation consists of two chapters. In chapter one the application of room temperature ionic liquids are briefly reviewed. The application of traceless synthesis of 3,5-disubstituted thiohydantoins are described in detail in the second chapter.There are five parts in chapter one. Part one deals mainly with properties of room temperature ionic liquids, including the structures and especial characteristics comparison with traditional solvent, Part two introduces the applications of ionic liquids to organic synthesis, including organic reactions in ionic liquids as green solvent. Part three recommends the application of ionic liquid to biologic catalysis, consisting with dissolution and catalysis of enzyme in ionic liquids, and process of separation and purification. Part four explains the latest development in task-specific ionic liquids, including ionic-liquid-supported peptides, oligosaccharide and organic compound synthesis. Part five illustrate the investigation of glucopyranosylidene-spiro-thiohydantoin for efficient inhibitor of muscle and liver glycogen phosphorylases.In chapter two, with two parts, the application of ionic-liquid-supported thiohydantoin derivates synthesis were investigated. In part one a novel linker was synthesized and applied to the synthesis of 3, 5-disubstituted thiohydantoins on functionalized ionic liquid support. The products separated readily, and the ionic liquid recovered conveniently. In part two the traceless synthesis of peptides were performed, but the peptides could not be cleavaged from ionic liquid. The synthesis of ionic-liquid-supported peptides need further research.