Direct Chiral Separations By High Performance Liquid Chromatography

With the development of science and technology , people deeply realize the distinguish between enantiomers for optically active compounds. It is becoming important to separate optical active compounds in the fields of biochemistry , organic chemistry, pharmaceutical chemistry as well as asymmetric synthesis and catalysis. There are many methods to separate optically active compounds. Among them, the high performance liquid chromatography (HPLC-CSP) is one of the rapid, most prospect methods in chiral separation. In the thesis, we emphasize on cellulose derivatives chiral stationary phase coated on silica gel.This paper consists of four parts:In the first part (chapter 1), the importance and methods of enantioseparation for chiral compounds have been reviewed systematically. It is given emphasis to development and types of cellulose chiral stationary phases . Especially application in enantioseparation and mechanism of chiral recognition of cellulose chiral stationary phases are mainly reviewed in detail.In the second part (chapter 2), Cellulose tris (4-methylbenzoate) was synthesized by the reaction of microcrystalline cellulose with benzoyl chloride. A chiral stationary phase was prepared by coating cellulose tris (4-methylbenzoate) on the silica .On the cellulose tris (4-methylbenzoate ) chiral stationary phase (CTMB-CSP), diclofop-methyl was resolved in normal-phase system. The influence of the composition of the mobile phase and the column temperature was investigated. were calculated and retention mechanism was researched.The third part (chapter 3 ) The asymmetric catalysis induced by metal framework chirality, instead of phosphine ligands, is alluring and difficult task in the field of catalysis. Today, there is rapid progress in synthesis of chiral metal clusters(l). It is very important to separate the metal clusters in order to gain adequate optical isomers, which can be used in catalysis. Unfortunately, separation of metal clusters is very difficult. Cellulose tris (3,5-dimethylphenylcarbamate) was prepared and used to chiral separation for five novel chiral metal clusters. The influence of alcohol such as the length of alkyl chain, steric bulkand content of alcohol in mobile phases were systematically examined. Based on the experimental results, the mechanism of the chiral recognition was discussed.The fourth part (chapter 4 ) a -phenylethanol was resolved on CDMPC and CTMB in normal-phase system. The influence of the composition and flow rate of the mobile phase was investigated. We choose the best experimental condition and determinate the excess value of the reaction.