Synthesis of 6-alkynylated uridines

Abstract
6-Alkynylated uridines, a hitherto unknown class of compounds, were synthesized by a coupling reaction of terminal alkynes with 6-iodo-2′,3′-O-isopropylidene-5′-O-methoxymethyluridine in the presence of bis(triphenylphosphine)palladium(II) chloride and copper(I) iodide. 6-Ethynyl-2′-deoxyuridine was also prepared by using 6-iodo-3′,5′-O-(tetraisopropyldisiloxan-1,3-diyl)-2′-deoxyuridine as a starting material.