Functionalized nucleoside 5′-triphosphates for in vitro selection of new catalytic ribonucleic acids

A series of novel 2′-modified nucleoside 5′-triphosphates was synthesized. The amino, imidazole, and carboxylate functionalities were attached to the 5-position of pyrimidine base of these molecules through alkynyl and alkyl spacers, respectively. Two different phosphorylation methods were used to optimize the yields of these highly modified triphosphates.