In conclusion, the synthesis of UAAs by means of sidechain decarboxylation of aspartic/glutamic acid has been presented. This simple protocol, requiring short reaction times and working at room temperature, allowed the incorporation of challenging electron-rich heterocycles on the lateral chain of novel UAAs, thus providing a more intuitive retrosynthesis of high-value targets. These aromatics, especially 5-membered ones, are underrepresented in previously reported UAAs, so novel building blocks are now available for usage in proteomics. Finally, other relevant features of this methodology are the use of readily available aryl bromides as well as the possibility to use cheaper variants based on (+)Al/(-)Nifoam electrodes.