Synthesis Of Chiral Amino Alcohols From L-Phenylglycine And Their Application

Two kinds of new chiral amino alcohol polydentate ligands obtained through synthesis were evaluated as chiral solvating agents for the chiral recognition of mandelic acid and its derivatives.On one side,5-tert-butyl-2-(dimethylamino)benzaldehyde was derived from4-tert-butyl aniline by dimethylation and formylation. A novel polydentate chiral amino alcohol (2S)-2-[(5-tert-butyl-2-dimethylamino)penyl] methyl-amino-2-phenylethanol was sythesized from5-tert-butyl-2-(dimethylamino)benzaldehyde and chiral amino alcohol prepared fom L-phenyl glycine with LiAlH4. The products were characterized by IR and1H NMR.One the other side, a nother novel polydentate chiral amino alcohol (2S)-2-[(5-tert-butyl-2-dimethylamino)phenyl]methylamino-1,1,2-triphenylethanol was prepared by condensation and reduction from5-tert-butyl-2-(dimethylamino) benzaldehyde and chiral amino alcohol obtained by esterification and Grignard reaction of L-phenyl glycine. The products were characterized by IR, GC-MS and NMR techniques.In addition, the chiral recognition ability of these two polydentate chiral amino alcohols were evaluated as chiral solvating agent (host) for7mandelic acid derivatives (guest) in the presence of an equimolar amount through1H NMR respectively. As a result, both of the two polydentate chiral amino alcohols got a certain chiral recognition ability, especially the latter polydentate chiral amino alcohol showed a better chiral recognition ability and the chemical shift non-equivalences (ΔΔδ) of4-tert-butyl mandelic acid enantiomers induced by the former was the largest37.6Hz. However, due to the time reason, further research on the chiral recognition ability of other chiral chemicals and the applications on asymmetric catalysis were also needed to explore.