Systematic Investigation on Acid-Catalyzed Truncation of N -Acylated Peptoids

Peptoids have emerged as a useful alternative to peptides. However, -acylated peptoids have occasionally undergone truncation at the terminal peptoid unit under acidic conditions. We previously reported on the mechanistic and electronic aspects of the acid-catalyzed truncation of -acylated peptoids. To gain further insight, we systematically investigated the conformational and electronic effects of the terminal side chains of peptoids. The → * interaction, based on -amide bond conformation, is considered to be one of the determining factors. In this study, it was demonstrated that both conformational and electronic factors contribute to this unusual truncation.