Total Synthesis of Sequential Retro‐Peptide Oligomers

Abstract

The total synthesis of sequential oligomers of retro‐peptides of the general formula Boc(‐gGly‐mAib)n‐OBn, starting from dimethylmalonic acid, has been carried out in good overall yield. The key step is the formation of the gGly unit >N−CH2−N<, which is easily obtained in a one‐pot/three‐step reaction from BnO‐mAib‐Gly‐OH and diphenylphosphoryl azide. The synthesis of the sequential oligomers of RCO(‐gAla‐mAib)n‐OR′ was also attempted, but the oligomerization step failed because the gAla moiety readily decomposes or racemizes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Synthesis and Crystallographic Characterization of Chiral Bis-oxazoline-amides. Fine-Tunable Ligands for Pd-Catalyzed Asymmetric Alkylations

“…The influence of the intramolecular distance between amidic moieties and oxazoline rings also was evaluated. With this aim, a new class of isopropylidene-bridged ligands 22 was designed with the related synthesis involving the use of malonic derivative 19 as the starting material …”

Oxalyl retro-peptide gelators. Synthesis, gelation properties and stereochemical effects

“…In this work we report on gelation properties, self-assembly motifs, chirality effects and morphological characteristics of gels formed by chiral bis(dipeptide)oxalamides. Structurally, such gelators belong to the group of retro-peptides, which have been intensively studied as peptidomimetics due to their higher proteolytic stability and bioavailability compared to natural counterparts [ 44 – 47 ]. Despite very promising biomedicinal properties, very little is known about the self-assembly potential of this class of compounds in solution.…”