Phosphorimidazolide

These phosphorus (V) compounds are encountered as reagents used for making new phosphoanhydride bonds with phosphate mono-esters, and as reactive intermediates in phosphoryl transfer reactions in some enzyme-catalyzed transformations.

Specifically, they have been proposed as the active electrophilic species which may have mediated the formation of inter-nucleotide phosphodiester bonds, thereby enabling template-directed oligonucleotide replication before the advent of enzymes.

The group has investigated a number of imidazole derivatives in the search for chemical moieties which provide longer oligonucleotides necessary for propagating genetic information.

[4] John D. Sutherland and colleagues have proposed that phosphorimidazolides may have formed in the chemical environment of early Earth via the activation of ribonucleotide phosphates by methyl isocyanaide and acetaldehyde followed by substitution with imidazole.

In one method, a phosphate mono-ester is dissolved in anhydrous pyridine[8] or N,N-dimethylformamide (DMF) and activated using triphenylphosphine (PPh3) and 2,2’-Dithiodipyridine (2,2’-DTDP) in the presence of triethylamine (TEA) base and excess imidazole.