Synthesis, conformational studies, X-ray structures, and complexation properties of semirigid macrocyclic phosphonamides

Macrocyclic precursors 6-9 reacted with 1,3-propanediol ditosylate or 1,2-dichloroethaene to derive semirigid phosphonamide ligands 1-5. Reactions for thiophosphoryl compounds 1 and 2 and phosphoryl derivative 5 were conducted in biphasic aqueous NaOH solutions. The 18- and 21-membered macrocycle products were characterized by a flexible crown ether part and a rigidified phosphoryl binding unit was integrated into the structure.