Chiral Perazamacrocycles: Synthesis and Applications. Part 2

The formation of chiral non-racemic perazamacrocyles containing three or more nitrogen atoms in the form of identical of different functionalities can be achieved by diverse methodologies which usually exploit the sequential formation of carbon-nitrogen bonds by reaction of nucleophilic nitrogen functions with electrophilic compounds. The rigidity and restricted flexibility of the reaction partners is generally a requisite for the successful cyclization, which can be alternatively accomplished by the use of a metal template. The carbon stereocenters in the formed macrocycle are generally present in the starting nitrogen-containing reagent, e.g. amine, diamine, -aminoacid and their derivatives. Intrinsically chiral porphyrins, lacking carbon stereocenters, have been also prepared. Chiral perazamacrocycles and their metal complexes have found applications in the fields of biomedical research, diagnosis, anion sensing, molecular recognition, enantiomeric discrimination, asymmetric catalysis, and material chemistry.