Replacement of the phosphorodiester linkages of RNA with guanidinium linkages: the solid-phase synthesis of ribonucleic guanidine

[reaction: see text] Replacement of the negatively charged phosphodiester linkages of RNA with positively charged guanidinium linkages provides the polycationic ribonucleic guanidine (RNG). RNG is anticipated to bind strongly to target DNA/RNA through the specific interactions of nucleobases and the attractive electrostatic interactions of backbones. Preparation of building blocks and the solid-phase synthesis of RNG are reported. Both trimeric and pentameric uridyl RNG have been synthesized.