Palladium-catalyzed allylation of pyrimidine-2,4-diones (uracils) and of 6-membered heterocyclic ambident sulfur nucleophiles
Pd(O)-Catalyzed allylation of six-membered ambident heterocycles bearing NH-CO, NH-CS and CH2-CO moieties obey the regioselectivity rules: C>O; N>O; S>N; NH-CO>NH-CS. Uracil and 5-methyluracil (thymine) do not show regioselectivity (N-1 = N-3) whereas 6-methyluracil is regioselectively allylated at N-3 (N-3>N-1).