Synthesis of Phosphoramidite Monomers Equipped with Complementary Bases for Solid-Phase DNA Oligomerization.

We describe the preparation of two monomers that bear complementary nucleobases at the edges (guanine-2'-deoxycytidine and 2-aminoadenine-2'-deoxyuridine) and that are conveniently protected and activated for solid-phase automated DNA synthesis. We report the optimized synthetic routes leading to the four nucleobase derivatives involved, their cross-coupling reactions into dinucleobase-containing monomers, and their oligomerization in the DNA synthesizer.