Concerted Fragmentation of N-Chloro-α-amino Acid Anions

Article abstract of DOI:10.1021/ja00350a046

The decomposition of anions of N-chloro-α-amino acids in neutral aqueous solution gives chloride ion, imines (which hydrolyze rapidly to amine and carbonyl products), and carbon dioxide.The reactions are first order in the concentration of the N-chloro-α-amino acid anions and are independent of acidity between pH 5 and 9.The rate constants, which range from 4.2 x 10^-6s^-1 to 9,0 x 10^-2s^-1 at 25.0 deg C, are highly dependent on the amino acid structure and values increase in the order: glycine < sarcosine < threonine < alanine < proline < α-aminoisobutyric acid < 1-amino-1-carboxycyclohexane.The factor of 21000 in relative reactivity for this sequence, the large positive values found for ΔS^<*> (30-61 J K^-1 mol^-1), and the products formed suggest that the reactions proceed by a concerted fragmentation mechanism.