Glycinamide complexes

The ammonioacetonitrile complex (206) reacts with NH3 to produce the amidine-bonded aminoacetamidine (207) complex, whereas in aqueous base it hydrolyzes to the amid o-A -bo ruled glycinamide complex (208).908 Acid-catalyzed linkage isomerization to first the O-bound form (209) precedes formation ultimately of the amino-bonded isomer (210) as the stable product upon deprotonation of the free amine above pH 6. 

The hydrolysis of glycinamide complexes of cobalt(m), viz. cis-[Co(en)2Br(glyNR R )] to give [Co(en)2(gly)] +, has been studied in alkaline solution by kinetic, stereochemical, and 0-labelling methods. The bromide ion is displaced first, and then comes cobalt-promoted hydrolysis... 

Copper(JI) has been found to inhibit the hydrolysis of glycylglycine in basic solution (pH> 11).127 Conley and Martin128 have also found that, at pH values in excess of 11, copper(II) inhibits the hydrolysis of glycinamide due to amide hydrogen ionization. Similar results were obtained with picolinamide, and a bis-picolinamide complex of nickel(II) containing deprotonated amide groups was isolated.128... 

In the case of amino acid ester and amide complexes, the intramolecular hydrolysis reaction was not observed directly, but was deduced from the results of lsO tracer studies. However, recently the cis-hydroxo and cis-aqua complexes derived from the bis(ethylenediamine)cobalt(III) system, containing glycinamide, glycylglycine and isopropylglycylglycinate, have been isolated and their subsequent cyclization studied over the pH range 0-14.160,161... 

Figure 11-7. Data table for multiple linear regression analysis of spectra of copper(II) complexes by UNEST. Ligand abbreviations GG, glycylglycinate Ga, glycinamide gly, glycinate en, ethylenediamine dien, diethylenetriamine 1,2-DAP, 1,2-diaminopropane tetmeen, tetramefnylethylenediamine. Data from E. J. Billo, Inorg. Nucl. Chem. Lett. 1974, 10, 613.

An addition which completely destroys the triple bond — but at the same time illustrates the synthetic usefulness of 100 - is demonstrated by the trapping of its etherate complex (see above) with dimethylamine under in-situ conditions the glycinamide 147 is isolated in 50% yield [92] according to Eq. (28). Formally, 100 has behaved in this transformation as an equivalent of the synthon 148 in the same sense as disodium acetylide (149) is synthetically equivalent to the dianion ISO. 

Similarly, chloral hydrate has been shown to form complexes (mainly l l) with acetyl glycinamide, 39 j O, 4l aine, 3> j caffeine, 8,49 diazepam,50,312 535-dimethylhydantoin, 52,307 phenacetin, 3j55 phenazone. 1>56 to 51 glycine,1, glucosel< °, urea53,6o and others. 

Several papers deal with ligand replacement (by edta and related ligands) in copper(ii) complexes. The role and structure of mixed-ligand intermediates in the displacement of trigly or glycinamide by edta or cydta have been discussed. 

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