An efficient palladium-catalyzed cross-coupling reaction of 4-hydroxy-pyrone or 4-hydroxy-2(5H)-furanone with arylboronic acid is described, which affords the 4-substituted-pyrones and 2(5H)-furanones in good yields. This transformation proceeds through a C-OH bond activation under mild conditions. (C) 2011 Elsevier Ltd. All rights reserved.
Generation of diverse 2-pyrones via palladium-catalyzed site-selective Suzuki-Miyaura couplings of 3-bromo-4-tosyloxy-2-pyrone
Based on different reactivity of the (pseudo)halide substituents in the 2-pyrone (3-Br and 4-OTs), palladium-catalyzed sequential site-selectiveSuzuki–Miyaura cross-coupling reactions of 3-bromo-6-methyl-4-tosyloxy-2-pyrone are described, which afford the diverse 2-pyrones in good yields.