6‑Iodopurine as a Versatile Building Block for RNA Purine Architecture Modifications

Natural modified bases in RNA were found to be indispensable for basic biological processes. In addition, artificial RNA modifications have been a versatile toolbox for the study of RNA interference, structure, and dynamics. Here, we present a chemical method for the facile synthesis of RNA containing C6-modified purine. 6-Iodopurine, as a postsynthetic building block with high reactivity, was used for metal-free construction of C–N, C–O, and C–S bonds under mild conditions and C–C bond formation by Suzuki–Miyaura cross-coupling. Our strategy provides a convenient approach for the synthesis of various RNA modifications, especially for oligonucleotides containing specific structures.