The in-fall of meteorites and interstellar dust particles during the Hadean–Archean heavy bombardment may have provided the early Earth with various reduced oxidation state phosphorus compounds and minerals, including phosphite (HPO32−)([Pi(III)]). The ion phosphite ([Pi(III)])has been postulated to be ubiquitous on the early Earth and consequently could have played a role in the emergence of organophosphorus compounds and other prebiotically relevant P species such as condensed P compounds, e.g., pyrophosphite ([PPi(III)]) and isohypophosphate ([PPi(III–V)]). In the present study, we show that phosphite ([Pi(III)]) oxidizes under mild heating conditions (e.g., wet–dry cycles and a prebiotic scenario mimicking a mildly hot-evaporating/drying pool on the early Earth at 78–83 °C) in the presence of urea and other additives, resulting in changes to orthophosphate ([Pi(V)]) alongside the formation of reactive condensed P compounds (e.g., pyrophosphite ([PPi(III)]) and isohypophosphate ([PPi(III–V)])) through a one-pot mechanism. Additionally, we also show that phosphite ([Pi(III)]) and the condensed P compounds readily react with organics (nucleosides and organic alcohol) to form organophosphorus compounds.

Cyclic canonical nucleotides are an important class of compounds playing broad roles in regulating biological processes and are investigated in the context of prebiotic chemistry as activated nucleotides for oligonucleotide formation. Despite their growing importance, synthetic access of 2 ,3 -cyclic nucleotides is constrained, resulting in their cost-prohibitive commercial prices. Here, we describe a microwave-assisted one-pot synthesis starting from commercially available nucleosides employing an easily available cyclophosphorylating reagent, bis(dimethyldiamino)phosphorodiamidate (BDMDAP). The corresponding 2 ,3 -cyclic nucleotides are isolated in good yields (70-91%) by a simple ion-exchange column with no further workup. The nucleosides require no protecting group as the cyclophosphorylation reaction is selective for the 2 ,3 -dihydroxyl groups. The experimental protocol is robust and can be run in parallel to provide access to gram quantities of these 2 ,3 -cyclic nucleotides within a day.