Studies On The Organic Synthesis Reactions Catalyzed By Solid Acids

This thesis consist of three chapters:In the first chapter, The paper summarized SO42-/MxOy (M = Ti, Zr, Fe) increasing extensive uses due to their unique acidity, high activity, high selectivity in organic reactions in recent years. They can almost catalyze all reactions which can be catalyzed by acidic catalysts and behave higher reaction acidity, better selectivity.In the second chapter, heteropoly acid (HPA) has been found to be useful catalyst in a variety of organic reactions in recent years. It is superior to common inorganic acids and has many advantages, such as high reactivity, non-toxic, inodorous, non-corrosive, non-pollution, non-volatile and excellent stability. Furthermore, HPA can be used not only as acid catalysts, but also as oxidative and bifuntional catalysts. We study the protection of hydroxyl group by formation of trimethylsilyl ethers and direct oxidation of trimethylsilyl ethers to the corresponding carbonyl compounds with the advantages of operational simplicity, high yields, short reaction times using phosphomolybdic acid (PMA).In the third chapter, Carboxylic esters have been extensively used in industry and commerce. They are synthesized by many methods. For example, esterification of carboxylic acids and alcohols, transesterification, alkylation of carboxylate anions and acylation of alcohols or phenols. On the other hand, ethers are also changed into esters by acylation. Some methods have not been entirely satisfactory due to drawbacks such as long reaction time, low yields, tedious work-up, emerging the problem of corrosivity, effluent pollution and the expensive, non-recoverable and unavailable catalysts. TiO2/SO42- is usually carried out at mild conditions with high yield and selectivity. The work-up of the reactions is very simple, high yields, short reaction times and recyclable and environment-friendly catalyst.