Et3N-induced demethylation-annulation of 3-alkynyl-4-methoxy-2- pyridones and structurally related compounds in the synthesis of furan-fused heterocycles
(Chemical Equation Presented) Various 3-iodo-4-methoxypyridin-2-ones and related pyrone and coumarin derivatives have been demonstrated as readily available precursors of 2-substituted furan-fused heterocycles by means of in situ sequential Sonogashira-acetylide coupling, dealkylation, and regioselective furan annulation reactions. A Et3N-induced SN2 process has been established that accounts for the dealkylation process.
Flexible strategy for differentially 3,5-disubstituted 4-oxypyridin-2(1H)- ones based on site-selective Pd-catalyzed cross-coupling reactions
(Chemical Equation Presented) 3,5-Dihalogeno-4-methoxy-N-methylpyridin- 2(1H)-ones have been shown to undergo single Suzuki coupling reactions in a site-selective fashion. Monoarylations occur at the C-5 position preferentially, thus leaving the remaining