1,4,6,10-Tetraazaadamantanes (TAADs) with -amino groups: synthesis and formation of boron chelates and host-guest complexes.

A synthetic route to 1,4,6,10-tetraazaadamantanes (TAADs) bearing free and protected amino groups at the bridge -atoms has been developed via intramolecular cyclotrimerization of C=N units in the corresponding tris(hydrazonoalkyl)amines. In a similar fashion, unsymmetrically substituted TAADs having both amino and hydroxy groups at the bridge -atoms were prepared via a hitherto unknown co-trimerization of oxime and hydrazone groups. The use of -TAAD derivatives as potential ligands and receptors was showcased through forming boron chelates and host-guest complexes with water and simple alcohols.