Stoichiometric Mono <i>N</i>‐Functionalization of Tetraazamacrocycles via Phosphoryl‐Protected Intermediates

The selective alkylation of one N atom of tetraaza macrocycles (1) occurs simply and in high yields according to the reaction sequence shown below. Compounds 2 and 3 can be regarded as cyclic analogues of hexamethylphosphoramide; they contain one reactive N atom in addition to three “inert” N atoms.