Facile nucleoside phoshorylation via hydroxyl activation

DNA synthesis without base protection

DNA synthesis can be achieved by using O-selective methods for internucleotide bond formation. This greatly simplifies the synthesis of oligodeoxyribonucleotides by eliminating the need for nucleobase protection and deprotection steps. This unit describes strategies that can be used for DNA synthesis without base protection. The discussion includes synthesis of phosphoramidite and H-phosphonate monomers, solid-phase assembly by the phosphoramidite and H-phosphonate methods, and future prospects for DNA synthesis using N-unprotected approaches.

Nucleotide synthesis via methods without nucleoside-base protection

Oligonucleotide synthesis via methods without nucleobase protection (N-unprotected methods) is briefly reviewed. The N-unprotected methods are advantageous in the following respects over conventional approaches that use protectors, generally, acyl protectors for the nucleobase (N-protected method). Two steps, introduction and removal of the protecting groups, are eliminated, and consequently use of undesirable reagents involved in these steps are avoided. In the synthesis of DNA oligomers, the risk of depurination of deoxyadenosine and deoxyguanosine derivatives, which is a serious problem in the N-protected methods, is considerably reduced. The range of synthesizable artificial analogues bearing base-labile functions is extended because harsh base treatment for the deprotection is eliminated.