We describe a novel method of polymerization, via the insertion of activated glycine esters into N-salicylideneglycinato-aquo-copper(II) chelate (1), that uses the reactivity of the metal chelate. In the absence of 1, a high molecular weight polyglycine was formed as a white precipitate after triethylamine was added to an N,N-dimethyl-formamide solution of 4-nitrophenyl glycinate (3a). In the presence of 5 mol % 1, however, the polymerization proceeded homogeneously. After the reaction mixture was poured into tetrahydrofuran, a condensation product of glycine was obtained. According to gel permeation chromatography analysis, the product consisted of high and low molecular weight fractions. The former and latter were obtained by self-polycondensation and polycondensation via the insertion of 3a into 1, respectively. So that the self-polycondensation of activated glycinates would be depressed, 2-chlorophenyl (3b), 3-chlorophenyl (3c), 4-chlorophenyl, and phenyl glycinates were used as less activated glycine esters. For the polymerization of 3b and 3c, the polymerization via the insertion of activated glycinates into 1 was promoted. (C) 2003 Wiley Periodicals,