Synthesis of Bicyclic Polyaza Polycarboxylic Macrocycles Containing a 12-Membered Unit

High dilution reactions between a diamine and a diacid activated with 1,3-thiazolidine-2-thione afforded bicyclic polyamines after reduction of the amido moieties with borane. The cyclisation yields ranged between 34 and 84% and presumably depend on the rigidity of the reagents. Selection of the most appropriate procedures for the deprotection of tosylated amino groups and for the addition of carboxylic groups appear to depend on the structure and the cavity size of the macrocycles. For instance, encapsulation of a Na⁺ ion as seen by ²³Na NMR prevents the substitution of the secondary amino groups of the polyaza ligands by acetate functions.

Polyaza polycarboxylic bis-macrocycles are synthesized from a diprotected tetraaza cyclic unit.