Expanding the catalytic repertoire of nucleic acid catalysts: simultaneous incorporation of two modified deoxyribonucleoside triphosphates bearing ammonium and imidazolyl functionalities.

Two nucleoside triphosphates, a pyrimidine modified with an ammonium functionality and a purine modified with an imidazolyl functionality are compatible with all conditions for a combinatorial selection of nucleic-acid catalysts. We believe that this work is the first to demonstrate the potential for using not one but two modified nucleotides in tandem. The potential for an enriched catalytic repertoire is envisioned.