Prebiotic Organic Chemistry of Diketopiperazines

ABSTRACT Even though the significance of amino acids and polypeptides is well recognized in broad prebiotic chemistry fields, 2,5‐diketopiperazines (DKPs) or cyclic dipeptides remains a mysterious species without clear relevance to the origin of complex biomolecular systems. The aim of this review article is to demonstrate the various roles and functions of DKPs in simulated prebiotic reactions reported over the past few decades. By highlighting both experimental and computational simulations, the formation and reaction of DKP derivatives in a range of prebiotically plausible conditions were discussed from the organic chemistry viewpoint, as the manuscript organization is predicated on fundamental reaction patterns such as photochemical synthesis, aminonitrile chemistry, and amino acid condensation. Analytical challenges of DKPs were identified through the literature review too, as the product detection and characterization are critical not only in prebiotic chemistry but also in synthetic organic chemistry fields. The collection and critical analysis of reports about prebiotically plausible processes of DKPs may imply the breadth of its chemical diversity including the potential relevance to nucleotides, value as a building block to more intricate biomacromolecules, and symmetry breaking.