Application Of Ionic Liquids And Ion-supported Compounds In Organic Synthesis

The dissertation consists of three chapters. In chapter one the applications of room temperature ionic liquids and (diacetoxyiodo)benzene to organic synthesis are briefly reviewed. The applications of an ion-supported (diacetoxyiodo)benzene to organic synthesis are described in detail in the second chapter. In chapter three the synthesis of urea derivatives and Henry reaction in ionic liquids are studied.There are two parts in chapter one. Part one deals mainly with the application of room temperature ionic liquids to organic synthesis, including the structures and features of ionic liquids, organic reactions in ionic liquids as green solvents, the latest development in task-specific ionic liquids. Part two introduces the applications of [bis(acyloxy)iodo]arenas such as (diacetoxyiodo)benzene and [bis(trifluroroacetoxy)iodo]benzene to organic synthesis, including a. oxidation of alcohols, b. oxidation of phenols, c. oxidative functionalization of alkenes, d. oxidative rearrangements and fragmentations, e. oxidations of sulfur, antimony and bismuth compounds, f. oxidative halogenation and generation of oxygen-and nitrogen-centered radicals. Several new, potentially useful structural types of [bis(acyloxy)iodo]arenas developed in recent years are also reviewed..In chapter two, with four parts, the applications of an ion-supported (diacetoxyiodo) benzene to organic synthesis were investigated. In part one an ion-supported (diacetoxyiodo) benzene was synthesized and applied to selective oxidation of alcohols in an ionic liquid. It was found that this system has high selectivity in oxidation of alcohols and the ion-supported (diacetoxyiodo)benzene can be recycled and reused. In part two three new types of ion-supported TEMPO catalysts were synthesized and could be used to catalyse selective oxidation of alcohols in water. Combination of the catalysts with an oxidant ion-supported (diacetoxyiodo)benzene in water consists of a green system for the oxidation in which both catalysts and oxidant can be recycled and reused. In part three oxidation of bromide with an ion-supported (diacetoxyiodo)benzene in ionic liquids afforded a clean path for bromination of alkenes. It was found that this reaction is highly stereoselective. In the last part selective oxidation of thiourea derivatives with an ion-supported (diacetoxyiodo)benzene in ionicliquids provided a method for the synthesis of 1,2,4-thiadiazolidines in high yields. The oxidant ion-supported (diacetoxyiodo)benzene can be recycled and reused for 6 times without decreasing its efficiency.In the last chapter two parts of contents were studied. Firstly, the synthesis of urea derivatives in an ionic liquid as a green solvent was evaluated and found that the reaction could be performed smoothly, the products separated readily, and the ionic liquid recovered conveniently. Secondly, with DBU as catalyst the Henry reaction could be well conducted in ionic liquids. The reaction features high reaction rate, high yields and low consumption of reactants. The phenomenon that the ionic liquids with different structures would impact on the Henry reaction greatly was observed.