A versatile and efficient template synthesis has been developed to synthesise novel polyamines [e.g. rac-N3-(3-aminopropyl)butane-1,3-diamine, isospermidine 1] via amino acids [e.g. (2R,4S/2S,4R)-N4-(3-aminopropyl)-2,4-diaminopentanoic acid] using cobalt(III) to assemble the three precursor components in a biomimetic manner.