Polymere Aminoschutzgruppen. Synthese von neuen poly[2‐(N‐vinylpyridinio)ethoxycarbonyl]‐,2‐(N‐pyridinio)ethoxycarbonyl‐ und 2‐(N‐4‐picolinio)ethoxycarbonyl‐geschützten Aminoderivaten und kinetische Untersuchungen zur basisch induzierten Aminosäurefreisetzung

Abstract

Abstract2‐Bromoethoxycarbonyl modified amino acids were reacted with pyridine, 4‐picoline and poly(4‐vinylpyridine) to yield the corresponding 2‐(N‐pyridinio)ethoxycarbonyl derivatives as water‐soluble amino‐protecting groups. The kinetics and activation energies of basicly induced cleavage of the amino acids were investigated by 1H NMR spectroscopy in a D2O/NaOD medium. The polymeric salts were found to be more reactive than the low molecular weight pyridinium bromides because of electrostatic polymeric effects. Additionally, the kinetic measurements confirmed a E1cB mechanism for the cleavage of the urethane function. The formation of peptide bonds was performed in the case of poly[2‐(N‐4‐vinylpyridinioethoxycarbonyl)]‐protected amino acids in aqueous medium by water‐soluble carbodiimides.