Highly Selective and Modular Synthesis of 3-Aryl-4-(arylethynyl)-2<i>H</i>-chromen-2-ones from 2-Iodoaryl 2-Arylacetates through a Carbonylative Sonogashira Coupling-Intramolecular Aldol Cascade Reaction
H-chromen-2-ones from 2-iodoaryl 2-arylacetates and arylacetylenes has been developed. The carbonylative Sonogashira coupling–intramolecular aldol casade reaction was carried out in the presence of Pd(PPh3)2(Cl)2 as the catalyst. The one-pot approach that involves the in situ formation of the 2-iodoaryl 2-arylacetates from the corresponding 2-iodophenols and 2-arylacetyl chlorides followed by the palladium-catalyzed
The invention provides compounds of the formula:
wherein B is a nucleobase selected from the groups (a) to (d):
and the other variables are as defined in the claims,
which are of use in the treatment or prophylaxis of hepatitis C virus infection, and related aspects.