Chiral Cryptates Derived from a Hexaazamacrocycle

The reactions of hexaazamacrocycle 1 with 2,6-bis­(bromomethyl)­pyridine
or 2,6-bis­[(tosyloxy)­methyl)]­pyridine in the presence of appropriate
carbonates result in the formation of derivatives of cryptand 6: enantiopure azacryptates of sodium and potassium. Crystal
structures of these compounds indicate interaction of a metal ion
with four pyridine nitrogen atoms and four tertiary amine atoms. The
competition reactions monitored by NMR spectroscopy indicate preferential
binding of Na+ over K+ as well as higher affinity
of 6 for Na+ in comparison with the [2.2.1]
cryptand.