Abstract
A phthalimide or 3-formylindole functionality was incorporated into a tris(hydroxymethyl)ethane (THME) scaffold, and the resulting compounds were subsequently transformed into phosphoramidites and solid supports. These building blocks were then used to synthesise oligonucleotides containing amine or aldehyde groups at various positions within their sequences. The resulting modified oligonucleotides were further conjugated through either amide bond formation or oxime ligation. These novel building blocks expand the repertoire of phosphoramidites and solid supports available for modifying oligonucleotides.