Department of Inorganic and Organic Chemistry and ‡Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague , Akademika Heyrovského 1203, Hradec Králové 500 05, Czech Republic.
Org Lett. 2015 Feb 6;17(3):520-3. doi: 10.1021/ol5035113. Epub 2015 Jan 23.
Migita-Stille coupling of (Z)-β-iodoacrylates with (E)-α-stannyl allylic alcohols to furnish 5-alkylidene-4-substituted-5,6-dihydro-2H-pyran-2-ones is efficiently catalyzed by 2% Pd black in DMF, while Pd(PPh3)4 is inactive. Heterogeneous Pd released in solution is most likely responsible for the catalysis. The reaction is applicable to other substrates, without having to resort to ligands, additives, and/or solid support for Pd. The resulting pyranones can be rearranged to fully functionalized pyranones in another single step.
（Z）-β-碘代丙烯酸盐与（E）-α-锡烯丙基醇的 Migita-Stille 偶联反应，在 DMF 中高效地被 2%钯黑催化，而 Pd(PPh3)4 则没有活性。溶液中释放的非均相钯很可能是催化反应的原因。该反应适用于其他底物，无需使用配体、添加剂和/或 Pd 的固体载体。生成的吡喃酮可以在另一个单步反应中重排成全功能化的吡喃酮。
