Several approaches towards asymmetrically derivatized peptide-decorated cyclens that yield lanthanide metal chelators, in which three of the nitrogen atoms of cyclen share a common substituent and the fourth nitrogen atom is differentially substituted, have been evaluated. The most effective route consisted of selective monoalkylation followed by peralkylation with a second different electrophile. The unique substituent also possessed ...
![2-[[2-[(2-chloroacetyl)amino]acetyl]amino]-3-phenyl-propanoic acid Structure](https://image.chemsrc.com/caspic/266/82784-65-4.png)