TY - JOUR A1 - Liu, Jiang A1 - Leonard, Peter A1 - Müller, Sebastian L. A1 - Daniliuc, Constantin A1 - Seela, Frank T1 - Nucleoside macrocycles formed by intramolecular click reaction: efficient cyclization of pyrimidine nucleosides decorated with 5'-azido residues and 5-octadiynyl side chains JF - Beilstein Journal of Organic Chemistry PY - 2018/// VL - 14 SP - 2404 EP - 2410 SN - 1860-5397 DO - 10.3762/bjoc.14.217 PB - Beilstein-Institut JA - Beilstein J. Org. Chem. UR - https://doi.org/10.3762/bjoc.14.217 KW - click cyclization KW - conformation KW - macrocycles KW - nucleosides KW - X-ray N2 - Copper(I)-promoted "click" cyclization in the presence of TBTA afforded nucleoside macrocycles in very high yields (≈70%) without using protecting groups. To this end, dU and dC derivatives functionalized at the 5-position of the nucleobase with octadiynyl side chains and with azido groups at the 5’-position of the sugar moieties were synthesized. The macrocycles display freely accessible Watson–Crick recognition sites. The conformation of the 16-membered macrocycle was deduced from X-ray analysis and 1H,1H-NMR coupling constants. The sugar conformation (N vs S) was different in solution as compared to the solid state. ER -