Synthesis Of Chiral Asymmetry Of The Aromatic Sweet Ammonia Alcohol

Chiral phenylglycinols are key chiral sources of various chemical applications, including drug synthesis, optical resolution of racemates and asymmetric catalysis, etc. These characteristics lead to a huge demand for chiral phenylglycinols. Thus, it is very important to develop a user-friendly preparation of chiral phenylglycinols.In chapter 1, the research progress in asymmetric synthesis of chiral phenylglycinols is reviewed. The asymmetric synthesis of chiral phenylglycinols used these years is also summarized including the pros and cons.In chapter 2, asymmetric synthesis of chiral phenylglycinols using chiral thionylaniline as chiral auxiliaries was studied.1) Synthesis of (S)-2-amino-2-(4-fluorobenzenyl) ethanol using chiral thionylaniline was conducted as a model reaction to determine its feasibility.2) In order to optimize the experimental conditions the effects of time on the preparation of Schiff s base, the investigations of 11 kinds of reducing agents and 3 types of the solvents on the reduction reaction, and of different reaction conditions on the removal of auxiliary were screened. The results showed that:a) asymmetric reduction of prochiral Shiff s base using BH3-THF, DIBAH as the reducing agents in 3 types of the solvents gave excellent stereoselectivities (ratio:97:3,95:5) and yields (>99%,>99%); b) chiral phenylglycinols could be obtained in high yield when HCl/MeOH used as the solvent, and chiral O-protected phenylglycinols were obtained when Et2O/HCl/MeOH used as the solvent; 3) under these optimized experimental conditions, a range of Weinreb amides was investigated. Chiral phenylglycinols with phenyl-monosubstituented or disubstituented, electron-withdrawing or electron-donating groups were obtained in 36-86% yield.