IN SITU PREPARATION OF NUCLEOSIDE PHOSPHORAMIDITES AND THEIR USE IN SYNTHESIS OF OLIGONUCLEOTIDES

摘要

The invention provides novel bifunctional phosphitylating reagents and their application in in situ preparation of 5'-protected nucleoside phosphoramidites and synthesis of oligonucleotides. Bifunctional phosphitylating reagents according to the invention react quickly with nucleosides under weakly acidic conditions. In addition, the bifunctional phosphitylating reagents according to the invention generate chemoselectively the corresponding nucleoside phosphoramidites in situ, without need to purify the nucleoside phosphoramidites before using them in oligonucleotide synthesis. Finally, the bifunctional phosphitylating reagents according to the invention are relatively stable and easy to handle.