Synthesis of Structurally Reinforced Chiral Macrocyclic Polyamines and Their Metal Complexes

Two structurally reinforced chiral 15-membered azamacrocycles (2S, 14S)-2,14-diisobutyl-10-methyl-1,4,7,10,13 -pentaazabicyclo[11.2.2]heptadecane and (2S,14S)-2,14-diisobutyl-7,10-dimethyl-1,4,7,10,13-pentaazabicyclo[11.2.2] heptadecane as a new type of ligand were conveniently synthesized by LiA1H4 reduction from their corresponding macrocyclic pseudopeptides cyclo[(2S,3′S)-2-(3′-isobutyl-2′-oxopiperazine-1′-yl)-4-methyl-pentanoyl-glycyl-glycyl-sarcosyl] and cyclo[(2S, 3′S)-2-(3′-isobutyl-2′-oxopiperazine -1′-yl)-4-methyl-pentanoyl-glycyl-sarcosyl-sarcosyl], respectively. Their copper(II) complexes were also prepared and characterized.