Privileged scaffolds in synthesis: 2,5-piperazinediones as templates for the preparation of structurally diverse heterocycles

Abstract

2,5-Piperazinediones (2,5-diketopiperazines, DKPs) can be viewed as privileged building blocks for the synthesis of heterocyclic systems. This tutorial review aims at underscoring the large number and structural variety of nitrogen heterocycles that are available by suitable manipulation of DKP starting materials, including many bioactive compounds and natural products.

Cyclic Peptides in Neurological Disorders: The Case of Cyclo(His-Pro)

“…Indeed, approximately 90% of CDP producers are bacterial (Giessen and Marahiel, 2014). The CDP scaffold can be synthesized either by purely chemically means using different solid phases or under reflux conditions in solution (Borthwick, 2012;Gonzalez et al, 2012) or, more naturally, by biosynthetic enzymes called nonribosomal peptide synthetases (NRPSs) and CDP synthases (CDPSs; Belin et al, 2012;Giessen and Marahiel, 2014). Common chemical synthesis of CDPs includes the condensation of individual amino acids at high temperature.…”

Unique Stereoselective Homolytic C−O Bond Activation in Diketopiperazine‐Derived Alkoxyamines by Adjacent Amide Pyramidalization

“…[39,40] For such biological applications, the structures of alkoxyamines should play an important role;i deally they should be biocompatible anda ssist binding to desired biological targets,afeature that is not given in current compounds of this type. Given that DKPs constitute al arge class of biologically active medicinally privileged scaffolds, [41][42][43] we hypothesized that ac ombinationo fa mino-acid-derived DKPs with nitroxides may prove attractive for potential biomedical applicationsa st heranostic agents.…”

Molecular Iodine‐Promoted Transimination for the Synthesis of 6‐Phenylpyrido[2′,1′:2,3]imidazo[4,5‐c]quinoline and 6‐(Pyridin‐2‐yl)pyrido[2′,1′:2,3]imidazo[4,5‐c]quinolines

“…Nitrogen-containing fused polyheteroarenes have continued to be invaluable structural frameworks in an umber of natural products and biologically and pharmaceutically activec ompounds. [14] In particular,t he pyridoimidazole [15] and imidazodipyridine [16] skeletons are ubiquitous structuralm otifs that have extensive applications in pharmaceutical and materials science. The pyridoimidazole framework is recognizeda sacentral pharmacophore of annulated dipyridoimidazoles (Glu-P1 and Glu-P2) and pyridino[1,2-a]imidazo [5,4-b]indole, which show promising anticancer [17] and antihypertensive [18] activity,r espectively ( Figure 1).…”