Chromium carbyne complexes amino acids

As has been demonstrated in Section 3.1.2.4, complexation of amino groups offers a quite different concept for reversible protection. Making use of this principle, the coordination of chromium carbyne complexes with amino acids was described as a new amino protection. Similarly, bis(ethylene-diamine)cobalt(III) complexes of amino acids constitute a new interesting method for protection which recently was extended to the development of a new type of anchoring in solid-phase synthesis (Scheme 69). First, a t-BOC amino acid is condensed with the aquabis(ethylenediamine)cobalt(lII) complex of p-aminomethylbenzoic acid. The handle obtained in this way is then linked to aminomethyl polystyrene to give the anchored amino acid (69). Due to the sufficient stability of the complex toward... 

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