Boranophosphate backbone: a mimic of phosphodiesters, phosphorothioates, and methyl phosphonates

Nucleoside boranophosphates are distinctive in that one of the non-bridging oxygens in the phosphate diester 1 is replaced by a borane moiety (BH 3 ). Although they retain the same net charge, BH 3 − -ODN have unique chemical and biochemical characteristics relative to other analogs. The change in polarity, lipophilicity, nuclease resistance, and the activation of RNase H cleavage of RNA in RNA: boranophosphate hybrids make boranophosphates very attractive for applications in enzymology and molecular biology and as potential antisense agents.