Reactions of mental chelates. I. The reactions of copper (II) chelates of some beta-diketones and their related compounds with glycine, diglycine and triglycine.
The reactions of copper(II) chelates of β-diketones such as acetylacetone, benzoylacetone, dibenzoylmethane and benzoylacetaldehyde and of chelates of their related compounds such as salicylaldehyde and 2-hydroxyacetophenone with glycine or glycylglycine were investigated. Only bis(salicylaldehydato)copper(II) and bis(benzoylacetaldehydato)copper(II) reacted with glycine to form the respective glycinato-Schiff base complexes, whereas the other chelates did not react with glycine under the same condition. On the other hand, all the chelates except bis(dibenzoylmethanato)copper(II) reacted with glycylglycine to form the respective glycylglycinato-Schiff base complexes. The reaction at pH 4.5 between bis(salicylaldehydato)copper(II) and triglycine resulted in the hydrolytic cleavage of peptide bond, producing the salicylideneglycylglycinatocuprate(II) and free glycine. As the results of this investigation, five new copper(II) chelates were synthesized and characterized.
Reactions of Metal Chelates. IV. The Reactions of Bis(salicylaldehydato)-copper(II) with Diethylenetriamine and Triethylenetetramine
The reactions of bis(salicylaldehydato)copper(II) with diethylenetriamine and triethylenetetramine were investigated under several different conditions. In water, in the absence of other reagents, the reactions gave uncharged bis (salicylaldehyde)-diethylenetriamine- and -triethylenetetramine-copper(II), respectively. In the presence of an acid the resulting complexes were the respective cation complexes, in which only one of the two terminal nitrogen atoms was in the form of Schiff base with salicylaldehyde. In the presence of a salt, the resulting complex from diethylenetriamine was a cation complex, and that from triethylenetetramine an uncharged complex. Three new copper(II) chelates were obtained.
A New Synthesis of Threonine
A new method is described for the synthesis of threonine from acetaldehyde and copper glycinate. This method gives a mixture of allo-threonine and threonine in a high yield (64%).