A Plausible Prebiotic One-Pot Synthesis of Orotate and Pyruvate Suggestive of Common Protometabolic Pathways.

A reaction between two prebiotically plausible building blocks, hydantoin and glyoxylate, generates both the nucleobase orotate, a precursor of biological pyrimidines, and pyruvate, a core metabolite in the citric acid cycle and amino acid biosynthesis. The reaction proceeds in water to provide significant yields of the two widely divergent chemical motifs. Additionally, the reaction of thiohydantoin and glyoxylate produces thioorotate in high yield under neutral aqueous conditions. The use of an open-chain thiohydantoin derivative also enables the potential pre-positioning of a nucleosidic bond prior to the synthesis of an orotate nucleoside. The observation that diverse building blocks of modern metabolism can be produced in a single reaction pot, from common reactants under mild conditions, supports the plausibility of orthogonal chemistries operating at the origins of chemical evolution.

A trans-bidentate bis-pyridinyl ligand with a transition metal hinge.

A titanocene based metalloligand, Cp*2Ti(C22-py)2, was synthesized and coordinated to either Cu(i) or Pd(ii). The metalloligand binds Cu(i) between its alkynes and Pd(ii) between its pyridinyl rings, acting as a trans-bidentate ligand. In order to bind Pd(ii), significant structural rearrangements were necessary, which required the flexibility of the C-Ti-C hinge on the titanocene metalloligand.