Chiral macrocycles complex formation

The ability of CDs to form intermolecular complexes with other molecules was already known in the early twentieth century. Another important property of CDs is that each glucose molecule in this macrocycle contains live chiral carbon atoms, which results in a chiral recognition ability in complex formation. This property of CDs was first evidenced by Cramer [1]. The relative easy availability from regenerable natural sources, the existence in various sizes, the stable structure, the localized hydrophobic area, the solubility in the hydrophilic solvents, the ability of intermolecular complex formation and the chiral recognition ability together with their nontoxicity, ultraviolet (UV) transparency, feasibility of their modification, and so forth contributed greatly to the establishment of CDs as a... 

Sterically more demanding copper(II) chelates based on trans-cyclohexane-1,2-diamine reveal similar condensation chemistry [165]. The yield of macrocyclic products, however, decreases compared to the reaction with ethane-1,2-diamine-containing chelates. The formation of copper(II) complexes of half-capped ligands is favoured compared to capped species for steric reasons. The presence of two asymmetric carbon atoms in the starting ligson allows synthesis of new chiral macrocycles. The most suitable for macrocyclisation has proved to be the R,R S,S bis(cyclohexane-l,2-diamine)copper(II). The three isomers of H2LI36 possible... 

Substitution of the terminal amine with ligating groups, such as catecholate, hydrox-amate or diketonate, lead to the formation of A-cis chiral complexes. In these structures the chiral information content is located in the amino acid bridges, instead of the macrocyclic peptide ring structure used in ferrichrome. It should be emphasized... 

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