Regio- and diastereo-selectivity of montmorillonite-catalyzed oligomerization of racemic adenosine 5'-phosphorimidazolide.

Clay is a possible candidate for an effective catalyst in prebiotic chemical evolution of biomolecules. Montmorillonite was reported to effectively catalyze oligomerization of racemic adenosine 5'-phosphorimidazolide (DL-ImpA). In the oligomerization reaction, considerable amounts of cyclic dimers as well as linear dimers were produced in the oligomerization reactions.

Characterization of Na+-montmorillonite-catalyzed reaction of racemic ribonucleotides.

We have reported that the oligomerization of racemic mononucleotides catalyzed by montmorillonite clay proceeds efficiently and gives up to 8-mer. Here, we attempted to identify the dimer products to show the characteristics of the racemic reaction. The results suggested that homochiral pApAs are formed in somewhat higher yield than heterochiral pApAs.