Its Application Glucose Assisted Asymmetric Synthesis Reactions In Organic Synthesis

With people’s further and further understanding for the important physiological function and potently pharmacological activity of complicated chiral enantiomer, the asymmetric synthesis has been developed rapidly and been a subject of intense research activity. Using chiral auxiliaries for the asymmetric synthesis is one of the most popular and practical methods. Carbohydrate not only exists widely in nature, but also is much accessible, inexpensive and environmentally friendly, which has been determined to be a valuable and effective chiral auxiliary for asymmetric synthesis.Herein we reported the novel methods for the stereoselective syntheses β,γ-unsaturated α-amino acids, α,β-diamino acids and β-hydroxy α-amino acids, using glucose and its derivatives as the auxiliaries. The research results are summarized below:1. The condensation reactions of the N-(2,3,4,6-tetra-O-pivaloylated-D-glucopyra-nosyl)amine with α,β-unsaturated aldehydes and the regio-and stereo-selectivity of the nucleophilic additions of trimethylcyanide to α,β-unsaturated aldimine have been studied. Based on the results of the experiments, it was proved that the optical glucopyranosyl group had played a significant role in the controlling of the regio-and stereoselectivity of the reaction. Therefore, a new method have been developed for the synthesis of β, γ-Unsaturated a-amino acids which are of great useful for their biologically significant properties, such as antitumor, antibiotic and enzyme inhibitory.2. The stereoselective nucleophilic additions of trimethylcyanide to aldimines which were prepared by condensation reactions of the N-(2,3,4,6-tetra-O-pivaloylated-D-glucopyranosyl)amine with N-Boc-phenylalaninals have been studied. Imines containing Glc derivatives and phenylalaninal two chiral auxiliaries, those two close chiral elements glucose and N-Boc-phenylalaninals would interact each other and making the induction reaction ambiguous and difficult to predict. Based on the results of the experiments, it was proved that the optical glucopyranosyl group had played a significant role in the controlling of the stereoselectivity of the reaction. By systematic variation of the N-Boc-phenylalaninals, a novel method for asymmetric synthesis of α,β-diamino acids has been developed.3. The stereoselective nucleophilic additions of trimethylcyanide to aldimine which is prepared by condensation reactions of the N-(2,3,4,6-tetra-O-pivaloylated-D-glucopyranosyl)amine with (R)-(-)-and (5)-(+)-2-[(tert-Butyldimethylsilyl)oxy]-2-phenylethanal have been studied. A novel method for asymmetric synthesis of β-hydroxy-α-amino acids which are widely present in macrocyclic polypeptides such as Lysobactin, Vancomicin has been developed.