The solid-phase synthesis (SPS) of phosphorus-containing compounds is based mainly on the fact that the chemical process is conducted in a two-phase system. One of the components is connected via covalent bonds to a solid support, which is in general an insoluble polymer, representing the solid phase of the process. The other components involved into the process are solubilized in a solution. The method is suitable to be applied to almost any organic compounds. A common example of using solid-phase synthesis is for obtaining products nucleotide containing, similar to nucleic acids. During the whole process, the nucleotide is always on the solid phase, after the condensation reaction, except for the last step, when the synthesis is already finished. Then, the product is released and separated very easily by filtration. The obtained polymer-oligonucleotide product can participate further in condensation reactions as well. Other important biomolecules synthesized by solid-phase approach during the last decades are nucleoside di- and triphosphates, nucleoside diphosphate sugars and dinucleoside polyphosphates. Those products are precursors of deoxysugars, aminodeoxysugars, uronic acids or glycoconjugates, and are also necessary for DNA and RNA synthesis. The use of the solid-phase method in the context of immobilized oligomers is of great interest nowadays. The solid-phase synthesis offers many advantages in comparison with the conventional solution-phase method, because it takes much less time, it is highly stereoselective, the products are separated and purified usually by a simple filtration or decantation, solvents with high boiling points could be used, the whole process is based on solid polymer support and the obtained compounds should not be isolated.
Solid-Phase Synthesis of Phosphorothioate/Phosphonothioate and Phosphoramidate/Phosphonamidate Oligonucleotides
