Development Of Chiral Aromatic Pyridoxamine Catalysts And Their Asymmetric Biomimetic Transamination Of ?-Carbonyl Peptides

Optically active a-amino acids are the basic building blocks of polypeptides and proteins,while polypeptides and proteins are the material components of organisms.Amino acids have special physiological functions in the body and are one of the indispensable nutrients for organisms.Many natural products and drug molecules contain amino acid structures.At present,there are many methods for synthesizing chiral ?-amino acids,of which the use of biomimetic pyridoxal/pyridoxime to catalyze the transamination of ?-keto acids has already provided a certain research basis,but for ?-carbonyl peptides.There is no research on transamination.This type of substrate is also widely used in biochemistry,pesticide chemistry and food additives.Based on the original pyridoxamine catalyst,the structure of the catalyst was modified and improved to realize transamination of the ?-carbonyl polypeptide compound.The work include the following three parts:(1)The original biaryl pyridoxamine catalyst was modified to select the optimalcatalyst.(2)Through the gradual screening of conditions,the optimal reaction conditionsare selected.(3)Design and synthesis of achiral and chiral substrates.The substrate has a widerange of applications.Under the optimal reaction conditions,the substrate wasextended in good yields with excellent ee's.