Synthesis of Modified Nucleosides. Palladium-Catalysed Couplings of Organostannanes or Organoboranes with Pyrimidine Nucleosides

Abstract

Coupling of suitably protected 5-iodouridine or 5-iodo-2′-deoxyuridine with either arylboronic acids or aryltrimethylstannanes in the presence of a palladium catalyst gave moderate yields of the corresponding 5-aryluridines and 5-aryC2′-deoxyuridines. 5-Hydroxyuridine was converted into 5-(trifluoromethanesulphonyl)uridine in good yield and the triacetate of this modified nucleoside also underwent palladium-catalysed couplings with a variety of organostannanes to produce the 5-substituted uridine in excellent yield.