A facile synthesis of new chiral [1+1] macrocyclic Schiff bases

A series of new chiral [1 + 1] macrocyclic Schiff bases have been synthesized in high yields and short reaction times from cyclocondensation of dialdehydes with long tethers and chiral diamines. The yields of the macrocycles were higher when the dialdehyde component is also chiral. The macrocyclisation was performed under microwave irradiation and aqueous reaction conditions employing salts of chiral diamines in contrast to free diamines normally employed.