Small Organic Molecules Catalyzed Synthesis Of Amides And Imidazole Derivatives

The development new synthetic methods under milder conditions, with high yields, high selectivity and atom economies become one of the popular research topics in modern organic synthesis. Catalytic synthesis become one of best choice according the above mentioned character. Among the huge catalyzed organic synthesis reaction, metal complexes, including the main group metal and transition metal, catalyzed organic synthetic reaction have very important position. However, most of the reaction catalyzed by metal complex have more or less problems, such as expensive catalyst, harsh reaction conditions, environmental pollution and difficult to recycle the catalyst and so on. Based on the reasons of economy and environment protection, organic molecules catalyzed reaction are of great interest in order to make the procedures of organic synthesis much cleaner, safer and easier to handle. Additionally, compared with metal complex using catalytic organic synthesis reaction, small organic molecules have many features, such as easy preparation, low cost, mild reaction conditions, good stability, and relatively stable to water and oxygen. So the reaction catalyzed by small organic molecules has attracted the huge attention of organic chemists.Based on the above research background, we have developed two new types of organic molecules catalyzed reaction for preparation of amides and imidazole derivates with high catalytic efficiency.This thesis consists of three chapters. In the first chapter, we simply review the classification, properties and applications of popular small organic molecular catalysts. At the end of this chapter, the chiral organic small molecules catalyzed the asymmetric synthesis methods are also mentioned.Amide is an important compound in organic synthesis. The classical method of preparation these compounds is conversion of ketoximes into corresponding amides, known as the Beckmann rearrangement, which has been tremendous interest to all practicing organic chemists. So, the new developed catalytic system of triphenylphosphine and iodine by used for Beckmann rearrangement reaction to preparation amide was reported in chapter two. After optimization of the reaction conditions, amide derivates were prepared with high yields by the new procedure. The reaction mechanism was also proposed. This new process has great advantages, such as inexpensive catalyst and simple post-treatment. All compounds were charaterized by IR,'H-NMR, HR-MS and some of them by 13C-NMR.Imidazole compounds are very useful building blocks in the synthesis of pharmaceuticals, natural products and ionic liquids. A new synthesis method for preparing imidazole compounds catalyzed by benzotriazole was reported in the third part of this thesis. Benzotriazole catalyzed the reaction of aldehydes, aromatic amines, ammonium acetate and 1,2-diphenyl dimethyl ketone reacted to provide three and four substituted imidazole compounds in n-butanol under 80℃.22 imidazole compounds with different substituents were synthesized and all characterized by IR, 1H-NMR and HR-MS. All the analysis dates are agree with the expected structure. The results of reaction show that this method can use a wide range substrate,simple post-treatment, fast response.