Site-specific modification of nucleobases in oligonucleotides

Abstract

Site-specific modification of oligonucleotides is a powerful approach for synthesis of oligonucleotides containing various derivatives of nucleobases, sugars, and phosphate backbones. By using this method, the structure of a modified moiety can be effectively screened to find artificial oligonucleotides having desired functions. In fact, many studies using a variety of site-specific modification methods have been reported to date. In this chapter, the site-specific modifications focusing on nucleobases within oligonucleotides are summarized. Moreover, as an experimental example of site-specific modification of an oligonucleotide, the preparation of N, N-disubstituted cytosine derivatives using reaction of 4-triazolylpyrimidin-2-one nucleobase with various secondary amines is demonstrated.