Recently we reported new terms 1a-b of this class of compounds in which the bridges are two equally substituted propylenes.
1) are synthesized in one-step: the assembling of the macrotricyclic structure is driven by the template effect of metal cation (Scheme 1);
Scheme 1. Synthesis of free ligands 1a-b.
2) are characterized by an increased lipophilicity;
3) the lateral chains can bear suitable functionalities for further synthetic transformations; and
4) can exist as two diastereoisomers, cis and trans, which can be separated by column chromatography.
