A regioselectively bis(thiourea)-substituted dibenzo-diaza-30-crown-10: a new strategy for the development of multi-site receptors

Due to our interest in the functionalization of dibenzo-30-crown-10 moiety, a regioselectively dinitro-derived congener 1 was conveniently synthesized . The availability of the compound as a building block to develop new molec ular systems allowed us to prepare a multi-site receptor 3, desirable for c ooperative complexation of cationic and anionic species in an induced fit f ashion. Indeed, K+ accommodated in the crowned cavity did not only tune the conformation to bind anions but also associated in the anion binding effic iently. (C) 2000 Elsevier Science Ltd. All rights reserved.