Study On The Catalytic Application Of Alkyl Iodides For Preparations Of α-tosyloxy Ketones In Organic Synthesis

This dissertation is on the application of using catalytic amount of alkyl iodides in organic synthesis. Alkyl iodides can be readily oxidized with a variety of oxidizing agents to hypervalent iodine intermediates, the in situ–generated active iodine species then reacts with substrates to afford the corresponding α-sulfonyloxy ketones and γ- butyrolactones in good yields. This thesis is divided into four chapters, which are as follows:1. We first summarize the progress of iodine(III) species with one sp3-carbon ligand in recent years, mainly including the property and the preparations of alkyl and fluoroalkyl iodosyl derivatives and the application in organic chemical reactions.2. The second chapter discusses the preparations of α-tosyloxy ketones. we have developed a new method for the direct formation of α-tosyloxy ketones through ketones with m-chloroperbenzoic acid and p-toluenesulfonic acid monohydrate in the presence of catalytic amounts of aliphatic iodine in a mixture of acetonitrile and 2, 2, 2-trifluoroethanol. Under the optimal reaction conditions, various alkyl ketons and aromatic ketones are tested to examine the generality of the current reaction. A possible reaction mechanism is also hypothesized.3. A more efficient and innovative method for preparations of α-tosyloxy ketones is provided in part three, which is based on previous work by using perfluoroalkyl iodides as the catalyst and m-chloroperbenzoic acid as the terminal oxidant in the presence of boron trifluoride ether and water in dichloromethane, and a series of α-tosyloxy ketones are obtained in good yields.4. Last part one, an efficient procedure for direct preparation of aryl-substituted lactones from corresponding aryl carboxylic acids is developed. In the present of a catalytic amount of ammonium iodide, aryl carboxylic acids are treated with potassium bromide and oxidant Oxone in a mixture of acetonitrile and 2, 2, 2-trifluoroethanol at room temperature, which resulting in corresponding aryllactones in moderate to good yields. The possible reaction mechanism is hypothesized.