Microwave assisted synthesis of 72-membered chiral hexanuclear [6+6] macrocyclic Schiff base

Abstract

Two new 72-membered chiral macrocyclic Schiff bases (1 and 2) possessing six salen pockets have been synthesized by employing a [6+6] cyclocondensation. The procedure involves short reaction time under microwave irradiation and aqueous reaction conditions. Moreover, the macrocycle synthesis uses salts of chiral diamines in contrast to free diamines normally employed. Spectral studies of these macrocyclic systems indicate the formation of diastereomeric structures.