4 - L-proline-substituted Chiral Catalyst Synthesis And ¦Â-cyclodextrin Inclusion Compound

A large number of chemical researchers are favored of the methodology and application of the asymmetric synthesis especially catalyzed by organocatalisis. At the same time, organocatalisis have played an important role in the fields of the synthesis and most of the reactions which were catalytyzed by organocatalisis can get much higher yield and good stereoselectivity.Proline is the most successful and widespread using of the organocatalysis but in some areas there are still shortcomings. Thus, a variety derivatives of proline were designed. For example, there are the prolinamide, prolinamide alcohol and the 4-substituted L-proline derivatives. All of them were synthesized in order to improve the solubility in organic solvents and get much higher yield and good stereoselectivity. This paper prepared several 4-substituted L-proline derivatives hoping to improve its solubility in organic solvents and also get good stereoselectivity. We start the Boc-trans-4-hydroxyproline as raw material to take place the William son and then remove the protection of Boc to synthesis several 4-substituted L-proline derivatives. Two of them were conformed inclusion complex withβ-CD. The structure's of the target products were characterized by IR.1HNMR,13CNMR and XRD.This thesis consists of four chapters:In chapter one:Firstly, give a full review of the types of proline and its derivatives about yield and stereoselectivity in catalyticing asymmetric reaction.Secondly, make a brief introduction of the present immobilization carrier of proline and its derivatives in catalyticing asymmetric reactions' types being included yield and stereoselectivity.In chapter two:several benzyl bromide reagents were synthesised by radical reactions.lt is found that the reaction can get different products in different solvents and tempreture. The substituents of benzene conversion is another factor. When the substituent group is electron withdrawing(-COOH,-Br), the reaction can be completed and highly conversed rate while when the substituent is the electron group(-OCH3), the raw materials always has a surplus and lowly conversed rate.In chapter three:Firstly, taking the Boc-trans-4-hydroxy-prolinemethylester as raw materia reacted with benzyl bromide under NaH then removing the protection to get (4R)-benzyloxy-(2S)-proline and (4S)-benzyloxy-(2S)-proline. On the basis of the former work, we also synthesize four 4-substituted L-proline derivatives by the same method instead of the Boc-trans-4-hydroxy-proline as the start material.We found that the different substituents of the benzene ring had a great influence on the reaction accrossing the experimental phenomena and results. When there is no substituent on the benzene ring, the reaction can occur at room temperature and the post-processing is simple. The reaction of allyl bromide and benzyl bromide are the good examples. While with a substituent the first step of the reaction always have the residual material leading to the complexity of the treatment of the reaction and the different substituents have different degrees of difficulty. If the substituent is the strong electron-withdrawing group such as -NO2,-COOH, the reaction is difficult to occur while the substituent is the electron-donating or weak electron-withdrawing group such as -CH3,-OCH3,-Br, the reaction is much easier compared to the former.In chapter four:Two inclusion complexes of the 4-substituted L-prolines'derivatives andβ-cyclodextrin were prepared by mixing solution.The inclusion was confirmed by the IR and XRD.Finally, the text is summarized.