J. Hovinen et al., NOVEL NON-NUCLEOSIDIC PHOSPHORAMIDITE BUILDING-BLOCKS FOR VERSATILE FUNCTIONALIZATION OF OLIGONUCLEOTIDES AT PRIMARY HYDROXY-GROUPS, Journal of the Chemical Society. Perkin transactions. I, (19), 1994, pp. 2745-2749
Synthesis of two non-nucleosidic phosphoramidite building blocks, 1a,
b, that enable attachment of various tether groups to oligonucleotides
at their 5'-terminus (or 1'-OH of 3'-deoxypsico-nucleoside units) is
described. Introduction of these linkers during the oligonucleotide as
sembly on a solid support, and their subsequent derivatization upon de
protection, afforded amino-, carboxy-, and sulfanyl-alkyl-thethered ol
igonucleotides.