Strategies Useful for the Chemical Synthesis of Oligonucleotides and Related Compounds

This review summarizes recent progress in useful strategies for the chemical synthesis of nucleic acids and related compounds surrounding the core of present author's works. Among the methods employed for internucleotide-bond formation, the phosphoramidite method is superior in many respects, including coupling efficiency, stability of building blocks, ease of automation, purity of the product, and synthetic applicability. The original phosphoramidite method has several drawbacks, and thus a great amount of effort has been focused on the development of promoters for internucleotide-bond formation, oxidation of the phosphite intermediate, protecting groups, and linkers and solid supports in order to broaden the synthetic applicability of this extremely useful method. The author's work to date, including the development of acid/azole complexes as promoters, anhydrous/non-basic oxidation methods, an AOC/allyl-protected strategy, will be highlighted, together with a discussion of the applicability of these methods for the synthesis of biologically important compounds.