The double selective synthetic approach is proposed for easy preparation of asymmetrically N-substituted derivatives of 1,4,7-triazacyclononane (tacn, [9]aneN(3)) with the same or different pendant arms. The synthetic routes simplify the synthesis of "tacn" ligands for functionalization of other carboxy terminated molecules/supports and also facilitate access to azamacrocycle functionalized self-assembled monolayer (SAMs) or nanopatterns for specific and stable Histidine-tagged protein immobilization.