The introduction of protective groups into multifunctional molecules, e. g. into amino acids for peptide synthesis, and their removal are one of the most important techniques and strategies in Organic Chemistry [2]. Amino acids, their anions and derivatives are versatile ligands, and the leading idea to protect the N- or C-terminus of amino acids by metal ions or by metal complexes has opened interesting chapters which reach from classical coordination and bioinorganic chemistry to modern organometallic and bioorganometallic chemistry [3]