The Synthesis Of Chiral Phase Transfer Catalyst And Its Application In Asymmetric Synthesis Compared

Asymmetric synthesis using chiral phase transfer catalyst is a new method that has just been developed in recent years. The purpose of this paper is to synthesize some phosphonium salts with PPh3 and some chiral quaternary ammonium salts with L-Valine. And we also use L-Valine and L-Phe-OMe to synthesize a new type catalyst —2,5-diketopiperazine , the simplest compound of cyclo-peptide. And then we use these phase transfer catalysts in a substitution reaction to test their catalytic function and asymmetric induction. According to the data from the substitution reaction, the catalytic function of the phosphonium salts and the chiral quaternary ammonium salts has been compared. The followings are the main work of my paper. 1. It summarized the development of asymmetric synthesis and the latest studies of phase transfer catalyst; 2. Use PPh3 as the starting material, by the reaction of quaterization we get four common phosphnium salts as PTC-1,PTC-2,PTC-3,PTC-4; 3. Use L-Valine as the starting material, by the reaction of esterification, neutralization and quaterization, we get three chiral quaternary ammonium salts as PTC-5,PTC-6,PTC-7;'4. Use L-Valine as the starting material, through the reaction with Methyl chloroformate in order to protect the –NH2, and then react...