A new versatile synthesis of macrotricyclic tetraazacycloalkane-based ligands from bis-aminal derivatives
Abstract
A new powerful synthesis of symmetrical (two-step) or dissymmetrical (three-step) macrotricyclic cyclen- or cyclam-based ligands is reported. In this procedure, the starting materials are bis-aminals derived from condensation of cyclen or cyclam with glyoxal. The two macrocyclic subunits are linked by two aromatic spacers through nitrogen atoms. © Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.