Solid-phase synthesis of P-boronated oligonucleotides by the H-boranophosphonate method.

Recently, P-boronated oligonucleotides have been attracting much attention as potential therapeutic oligonucleotides. In this study, we developed H-boranophosphonate oligonucleotide bearing a borano group and hydrogen atom on the internucleotidic phosphorus and demonstrated that this novel P-boronated oligonucleotide is a versatile precursor to various P-boronated oligonucleotides such as boranophosphate, boranophosphorothioate, and boranophosphoramidate. The method was also applicable to the synthesis of a locked nucleic acid-modified boranophosphate oligonucleotide, which exhibited a dramatically enhanced affinity to complementary oligonucleotides.