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The origins of life represent one of the most fundamental chemical questions being addressed by modern science. One of the longstanding mysteries of this field is what series of chemical reactions could lead to the molecular biologists dream; a pool of homochiral nucleotides? Here we summarize those results we consider to be historically important and outline our recently published research aimed at understanding the chemoselective origins of the canonical ribonucleotides. 1 Introduction 1.1 Nucleotides: What's the Problem? 2 Synthesis of Activated Pyrimidines 2.1 Pyrimidine Elaboration by Cyanovinylation 2.2 Photochemical Epimerization and Cytidine to Uridine Conversion 2.3 Urea-Mediated Phosphoryl Transfer and Intramolecular Rearrangement 2.4 Pyrimidine Photosanitization 3 Chemoselective Purine Glycosylation 4 Future Scope for Investigation 5 Conclusion [ABSTRACT FROM AUTHOR]

Monoalkyl phosphates can take the place of carboxylic acids in the Passerini reaction, but excesses of aldehyde and isonitriles are required, and transfer of the phosphate to the newly formed hydroxyl group does not take place. By rendering the phosphate addition intramolecular, the efficiency of the reaction is substantially increased. Phosphate transfer can take place when cyanovinyl phosphate is used rather than a monoalkyl phosphate. [ABSTRACT FROM AUTHOR]

Described are our preliminary studies on the reactivity of thiophosphate in a setting which correlates with the cyanosulfidic systems chemistry we have previously reported. Thiophosphate adds to various nitrile groups giving the corresponding thioamides in a highly efficient manner and the mechanistic implications are briefly discussed. Thiophosphate can also act as a phosphorylating agent, which was demonstrated with adenosine. The prebiotic availability of thiophosphate must be questioned, but if a plausible synthesis can be found, the advantages it would bring to the field of prebiotic chemistry appear to be highly beneficial. [ABSTRACT FROM AUTHOR]