I2 or I2/PIFA one-pot induced system for rapid synthesis of chalcogenated enamides, uracils or 2-pyridones under mild conditions

Abstract

We have developed a protocol for the β-C(sp²)–H chalcogenylation of both endo- and exo-cyclic enamides using stoichiometric amounts of molecular iodine and dichalcogenides at room temperature, completing the reaction within a mere five minutes and in an open-air environment. This method yields a diverse array of sulfenylated and selenated enamide compounds, including 5-phenylsulfanyl and 5-phenylselanyl uracil, under mild and metal-free conditions. Treating the endo-cyclic chalcogenated enamides with PIFA for five minutes, through a sequential one-pot process, leads to valuable 5-thio- and 5-seleno-2-pyridones with a free C-3 position.