Expeditious, Potentially Primordial, Aminoacylation of Nucleotides

In the beginning: Mixed carboxylic phosphoric anhydrides 3, formed from 3′-nucleotides 1 and amino acid N-carboxyanhydrides 2, undergo competing rearrangement to 2′-aminoacyl esters 4 and cyclization to 2′,3′-cyclic phosphates 5. The intramolecular aminoacyl transfer is faster than the cyclization despite the ease with which 2′,3′-cyclic phosphates are formed through any other form of phosphate activation.